Skip to main content

High-Hole-Mobility Metal–Organic Framework as Dopant-Free Hole Transport Layer for Perovskite Solar Cells

Abstract

A dopant-free hole transport layer with high mobility and a low-temperature process is desired for optoelectronic devices. Here, we study a metal–organic framework material with high hole mobility and strong hole extraction capability as an ideal hole transport layer for perovskite solar cells. By utilizing lifting-up method, the thickness controllable floating film of Ni3(2,3,6,7,10,11-hexaiminotriphenylene)2 at the gas–liquid interface is transferred onto ITO-coated glass substrate. The Ni3(2,3,6,7,10,11-hexaiminotriphenylene)2 film demonstrates high compactness and uniformity. The root-mean-square roughness of the film is 5.5 nm. The ultraviolet photoelectron spectroscopy and the steady-state photoluminescence spectra exhibit the Ni3(HITP)2 film can effectively transfer holes from perovskite film to anode. The perovskite solar cells based on Ni3(HITP)2 as a dopant-free hole transport layer achieve a champion power conversion efficiency of 10.3%. This work broadens the application of metal–organic frameworks in the field of perovskite solar cells.

Graphical Abstract

Introduction

Organic–inorganic hybrid perovskite solar cells (PSCs) are drawing more and more attention due to its rapid upgrade of device efficiency [1,2,3,4,5,6,7,8,9]. So far, the highest certified power conversion efficiency (PCE) of the PSCs has reached up to 25.5% [10], approaching that of monocrystalline silicon-based solar cells. PSCs are thin-film devices, and the perovskite light active layer is sandwiched between anode and cathode. To improve the PCE and stability, the suitable hole transport layers (HTLs) are inserted between perovskite layers and anodes [11,12,13,14,15]. Usually, HTLs have been proven to be an important part of PSCs to reduce carrier recombination and collect holes effectively, thereby increasing open-circuit voltage and fill factor [16]. Ideal HTLs should incorporate the following desirable characteristics: (i) high carrier mobility to facilitate effective transportation holes. (ii) high stability to prolong device life. (iii) low-temperature solution process for deposition of the film.

The HTLs are divided into organic and inorganic materials. The organic HTLs have high-quality film and adjustable bandgap [17, 18]. The representative organic materials used in perovskite solar cells are poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) [19], poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] [20], 2,2′,7,7′-tetrakis(N,N′-di-p-methoxyphenylamine)-9,9′-spirobiflurorene (Spiro-OMeTAD) [21] and poly(3-hexylthiophene) [22,23,24,25]. However, the hole mobility of the most organic HTLs is within 10−2–10−6 cm2·V−1·S−1 [26]. It limits the ability to transport holes from active layer to electrode and further restricts device efficiency. Doping is a useful method to enhance carriers mobility of organic semiconductors. For example, the hole mobility improves enormously after 4-tert-butyl-pyridine and bis (trifluoromethane) sulfonimide lithium salt are added into Spiro-OMeTAD. However, it also brings the problem of device instability due to the hygroscopicity of the additives, and so on [27, 28].

Traditional inorganic materials such as V2O5, Cu2O, MoO3, CuSCN, NiOx, and their derivatives have been widely studied due to the advantages of excellent long-term stability and high intrinsic hole mobility [29,30,31,32,33,34]. Nevertheless, most of these materials are prepared through high annealing temperature, O2 plasma, too time-consuming, or limited solubility. These drawbacks hinder their further development in large-scale applications and flexible devices. Therefore, it is necessary to find new HTLs with high mobility, low-temperature process, and high stability.

Metal–organic frameworks (MOFs) possess properties of high degree flexibility, including adjustable electrical [35], optical [35], and mechanical properties [36, 37]. It has attracted much attention in the fields of electronic devices [38, 39], such as memristors, field-effect transistors, supercapacitors [40], and various sensor architectures [41,42,43]. In recent years, MOFs have been applied in PSCs due to the properties of regular micro-pore structures and low-temperature process [44,45,46,47,48]. Vinogradov et al. first reported the TiO2-MOF-based solar cells with an efficiency of 6.4% [49]. Utilizing the typical micro-pore structure of MOFs, Ho et al. introduced MOF-525 (Zr6O4(OH)4(TCPP-H2)3) as the regular scaffold into perovskite film to mediate the arrangement of perovskite crystallites. Finally, they improved the morphology and crystallinity of the perovskite thin film [50]. Wei and coworkers used zeolitic imidazolate framework-8 as an interface layer to increase the crystallinity and grain size of perovskite film [51]. Fan et al. doped [In2(phen)3Cl6]·CH3CN·2H2O into HTLs to enhance light absorption and reduce the pinholes of the film [52]. These works improved PSCs performance effectively by regulating the morphology and crystallinity of perovskite film via adding MOFs. However, to our knowledge, MOFs as dopant-free HTLs in PSCs have not been reported. In recent years, the emergence of electrically conductive MOFs provides new opportunities for their integration as electroactive components in electronic devices [53].

Herein, we firstly attempt Ni3(2,3,6,7,10,11-hexaiminotriphenylene)2 (Ni3(HITP)2) as dopant-free HTLs in PSCs to extract holes effectively for PSCs. The Ni3(HITP)2 is a p-type semiconductor material with a high hole mobility of 48.6 cm2·V−1·s−1 [54], and the Ni3(HITP)2 film can be synthesized in a low-temperature process. The thickness controllable floating film of Ni3(HITP)2 at the gas–liquid interface is transferred onto indium tin oxide (ITO)-coated glass substrate. The film possesses low surface roughness, which provides prerequisites for subsequent deposition of high-quality perovskite films. Steady-state photoluminescence (PL) spectrum shows Ni3(HITP)2 film can transport holes effectively from perovskite layer to anode. As a result, the inverted planar PSCs based on Ni3(HITP)2 film achieve the champion PCE of 10.3%.

Results and Discussion

The Ni3(HITP)2 film is transferred by the following method, and experimental details are provided in the experimental section and Additional file 1: Figure S1. After the reaction mixture is heated to 65 °C, a bluish film spontaneously spreads out and forms at the liquid–air interface because of the hydrophobic of the Ni3(HITP)2 film. Then, the ITO-coated glass substrate is placed at the air–liquid interface along the edge of the beaker in an inclined posture under the film. The side of the Ni3(HITP)2 film contact with water directly adsorbs on the ITO-coated glass substrate by homeopathically and slowly lifting. Finally, a complete Ni3(HITP)2 film is obtained. Figure 1a shows X-ray diffraction (XRD) characterization. The peaks of the XRD spectrum are located at 4.7°, 9.5°, 12.6°, 16.5°, and 27.3°. The peaks of 4.7°, 9.5°, 12.6°, and 16.5° correspond to the (100) reflections, and 27.3° originates from (001) reflection. The result is consistent with the structure of Ni3(HITP)2 reported in the previous literature [54]. The transmission electron microscope (TEM) result in Fig. 1b displays that the film is highly oriented and uniform without curling on the edges of these nanosheets. The Ni3(HITP)2 has a fringe spacing of 1.884 nm, corresponding to the (100) plane [55]. The energy-dispersive spectroscopy mapping images (Additional file 1: Figure S2) reveal the uniform element distribution of Ni, C, and N throughout the whole Ni3(HITP)2 film. X-ray photoelectron spectroscopy (XPS) (Additional file 1: Figure S3) is further carried out to identify the formation of Ni3(HITP)2 film. As shown in Fig. 1c, there are no other impurities such as NiO (853.8 eV) and Ni(OH)2 (855.2 eV) in the membrane, according to the previous reports [21]. The peaks of Ni 2p are located at 873.4 eV (2p1/2) and 855.5 eV (2p3/2) from Ni3(HITP)2 [54]. In addition, the thermogravimetric analysis is conducted to investigate the stability of the Ni3(HITP)2 film. As can be seen from Fig. 1d, water in the film is lost at the initial stage. As the temperature increases, Ni3(HITP)2 decomposes between 300 ℃ and 520 ℃. The high thermal stability provides wider application compared with organic materials.

Fig. 1
figure 1

Characterization of the Ni3(HITP)2 film. a XRD pattern, b TEM micrograph; c XPS spectra of Ni 2p, and d thermogravimetric curve of the Ni3(HITP)2

By controlling the reaction time, we obtained the different thickness films (Additional file 1: Figure S4). The Ni3(HITP)2 film gradually changes from light blue to bluish-black or even black as the film thickness increases (Additional file 1: Figure S5). Figure 2a shows the optical transmittance of Ni3(HITP)2 films with different thicknesses. The transmittance of these films decreases with increasing film thickness. The films with thickness of 20 and 30 nm maintain over 75% transmittance. The hole mobility of the Ni3(HITP)2 films reaches up to 48.6 cm2·V−1·s−1, and it is higher than that of most hole transport materials and even some inorganic materials. The high carrier mobility is conducive to hole transportation in photo-electronic devices [56]. The electronic properties of the Ni3(HITP)2 film are further conducted by ultraviolet photoemission spectroscopy (UPS) (Fig. 2b). The Femi level (Ef) of 4.48 eV and valence band maximum (VB) of 4.98 eV are obtained from the secondary electron cutoff and the onset of the UPS spectra according to the following equations: Ef = hvEcutoff and VB = hv − (EcutoffEonset), where hv is the incident photon energy of the He (I) source (21.22 eV). Figure 2c shows the energy level alignment diagram of the inverted PSCs. The result demonstrates that the VB of Ni3(HITP)2 and perovskite (~ 5.4 eV) are matched well. It indicates the Ni3(HITP)2 film is desirable to act as HTL for PSCs. Steady-state PL spectra is performed to ascertain the hole transfer ability from perovskite film to Ni3(HITP)2 layer (Fig. 2d). After introducing PEDOT/PSS, the perovskite films show strong PL quenching, indicating the holes are transferred from perovskite to HTL of PEDOT/PSS. The PL of perovskite film is further quenched, when Ni3(HITP)2 replaces PEDOT/PSS. Especially, 30 nm Ni3(HITP)2 film leads to the lowest PL intensity, suggesting more carriers are transferred effectively from perovskite to HTL. In addition, we have repeated the PL of 20 nm and 30 nm Ni3(HITP)2 for three times to compare with other thicknesses of Ni3(HITP)2 (Additional file 1: Figure S6). The graphs marked with the red box are the PL of perovskite with 20 nm and 30 nm Ni3(HITP)2 and are further amplified in the inset of Additional file 1: Figure S6. The time-resolved PL measurement is carried out to analyze the hole extraction capability of Ni3(HITP)2 film (Additional file 1: Figure S7). The average decay lifetimes of the perovskite deposited on ITO substrate with different hole transport layers are listed in Additional file 1: Table S1. Compared with PEDOT/PSS, the average carriers lifetime of perovskite drops greatly upon introducing Ni3(HITP)2 film, indicating that the holes can efficiently be extracted at the interfaces of perovskite and Ni3(HITP)2. It is worthy of noting that the shorter decay lifetimes perovskite based on the 30 nm Ni3(HITP)2 film declines to 1.18 ns, revealing its high carrier extraction capability.

Fig. 2
figure 2

Characterization of optical and electrical properties of Ni3(HITP)2 film. a Optical transmission spectra of different thickness of Ni3(HITP)2 films; b UPS spectra of Ni3(HITP)2 film; c Energy level alignment diagram of PSCs and d The steady-state PL spectra of perovskite films on different thickness Ni3(HITP)2 films

To investigate the surface quality of the Ni3(HITP)2 films with different thicknesses, scanning electron microscopy (SEM) images are exhibited in Fig. 3. Compared with the ITO-coated glass substrate, both 20 nm and 30 nm thickness of the Ni3(HITP)2 films remain the similar state of ITO, manifesting highly transparent property. Further increasing the thickness of films, the surface morphology character of the ITO disappears. Meanwhile, the film becomes non-uniform and has some white spots. Figure 3f and Additional file 1: Figure S8 show the surface morphology of Ni3(HITP)2 films by atomic force microscopy (AFM). The root-mean-square (RMS) roughness is 9.74 nm for the Ni3(HITP)2 films with a thickness of 20 nm. When increasing to 30 nm thickness, RMS roughness increases to 5.5 nm. Nevertheless, further increasing the thickness of Ni3(HITP)2 films, the film surface becomes rougher with RMS roughness of 14.2 nm and 16.3 nm for 40 nm and 50 nm thickness of Ni3(HITP)2 films, respectively. The results of AFM and SEM show that the Ni3(HITP)2 film with a thickness of 30 nm has a smooth and compact surface. It is the guarantee for subsequent deposition of high-quality perovskite film for solar cells.

Fig. 3
figure 3

Morphology characterization of Ni3(HITP)2 films with different thicknesses. SEM images of a Bare ITO-coated glass and be Ni3(HITP)2 films with 20 nm, 30 nm, 40 nm, 50 nm, respectively; f AFM image of Ni3(HITP)2 film of 30 nm thickness

To investigate the morphology and crystallinity of the perovskite films on Ni3(HITP)2 films, Fig. 4 and Additional file 1: Figure S9 show the surface SEM images and XRD pattern of perovskite film. The perovskite layer is prepared by a two-step method, which avoids Ni3(HITP)2 film being corroded by the solvent N, N-dimethyl formamide and dimethyl sulfoxide. As can be seen from Fig. 4, all the perovskite films based on different thicknesses of Ni3(HITP)2 films have compact surfaces, but they still have obvious differences. The grain boundary of perovskite film deposited on the 20 nm Ni3(HITP)2 film is clearly visible. When increasing the thickness of the Ni3(HITP)2 film to 30 nm, the perovskite grain boundaries gradually become blurred. It indicates the perovskite grains are closely packed together. Meanwhile, the perovskite grain size is increased to 2 um, contributing to the smoother film surface of Ni3(HITP)2 film. When further increasing the thickness of Ni3(HITP)2 film, the perovskite grains become smaller, and the perovskite film surface gets uneven. Furthermore, Additional file 1: Figure S9 further shows the quality of perovskite films deposition on different thicknesses of Ni3(HITP)2 membranes. It can be seen that the XRD peak intensity of the perovskite deposited on the surface of the 30 nm-thick Ni3(HITP)2 film is higher than that of other thicknesses of perovskite films. The results demonstrate the perovskite film with 30 nm Ni3(HITP)2 has the highest crystallinity.

Fig. 4
figure 4

Morphology characterization of perovskite films deposition on different thicknesses of Ni3(HITP)2 films. ad 20 nm, 30 nm, 40 nm, and 50 nm, respectively

To build up a good performance solar cell, the Ni3(HITP)2 films with a thickness of 30 nm are used to fabricate the p-i-n type inverted PSCs due to its high transmittance, good flatness, high hole mobility, and appropriate energy level. Figure 5a shows the device has clear layers from the cross-sectional view and the thickness of perovskite is about 300 nm. The JV measurement of PSCs is conducted under the standard AM 1.5G illumination. As shown in Fig. 5b, the device exhibits a negligible photocurrent hysteresis under different scanning directions [57, 58]. The champion device has a PCE of 10.3%, Voc of 0.91 V, Jsc of 17.09 mA·cm−2, and FF of 66%. Figure 5c shows the steady-state photocurrent density and efficiency evolved with time at the maximum power output point (0.75 V). A reliable output efficiency of 9.61% and photocurrent density of 15.45 mA·cm−2 are obtained. Figure 5d shows the external quantum efficiency (EQE) of the device. The integrated Jsc from the EQE spectrum is 16.94 mA·cm−2, which is consistent with the value from the JV curve. The EQE of the device is no more than 73% at the wavelength between 400—800 nm. To overcome the problem, the Ni3(HITP)2 film is inserted between perovskite film and top electrode will be a good strategy. This kind of work is underway. In addition, Fig. 5e illustrates the good reproducibility of the devices with the PCE histogram collected from 22 independent devices.

Fig. 5
figure 5

The characterization of the PSCs. a The device structure and SEM image of cross section; b the JV curves of the device under forward scan and reverse scan; c steady-state photocurrent (black curve) and output efficiency (red curve) of the device; d EQE and corresponding integrated Jsc; e histogram of PCEs measured from 22 PSCs

Conclusions

In summary, a dopant-free Ni3(HITP)2 endows the suitable valence band edge and high hole mobility as HTLs for PSCs. The steady-state and time-resolved PL spectrum exhibit high hole extraction capability of Ni3(HITP)2. Inverted PSCs based on Ni3(HITP)2 films have a champion PCE of 10.3%. This work fills the gap in the application of MOFs as dopant-free hole transport layers in PSCs and expands the application field of MOFs.

Materials and Methods

Materials

All the chemicals were bought from commercial resources without additional purification. Water was purified with the Milli-Q purification system. Nickel chloride hexahydrate and ammonium hydroxide were bought from Sinopharm Chemical Reagent Co. 2,3,6,7,10,11-hexaaminotriphenylene hexahydrochloride was bought from WuXi AppTec. Lead (II) iodide was obtained from Sigma-Aldrich.

Synthesis of the Ni 3 (HITP) 2 Film

20 mg of 2,3,6,7,10,11-hexaaminotriphenylene hexahydrochloride, 13.2 mg of nickel chloride hexahydrate, and 40.0 mL H2O were added into a 50-mL beaker. The reaction mixture was then sonicated until the solids were completely dissolved. After that, 0.6 mL ammonium hydroxide was dropped into the beaker when the reaction mixture was heated to 65 °C. The Ni3(HITP)2 film was formed at the air–liquid interface after 1 min. Different thickness of the films was controlled by the reaction time.

Device Fabrication

ITO-coated glass substrates were sequentially cleaned by sonication with acetone, deionized water, and ethyl alcohol and then were treated using UV-ozone. The processed ITO glass was extended to the bottom of the film along the edge of the beaker in an inclined posture. The complete Ni3(HITP)2 film was obtained by homeopathically and slowly lifted onto ITO-coated glass substrate. Then, after further cleaning and drying the Ni3(HITP)2 film adsorbed on ITO-coated glass substrate, the perovskite layer was fabricated as described in our previous report [57]. The electron-transporting layer, PC61BM (methyl [6, 6]-phenyl-C61-butyrate) (20 mg/mL in chlorobenzene) was deposited by spin-coating. Finally, the Ag electrode was thermally evaporated in a high vacuum chamber through a metal mask. The device’s effective area was 0.0725 cm2.

Characterization

The morphologies images were obtained using AFM (Bruker) and SEM (Hitachi SU8010). The TEM images were obtained by using FEI Tecnai F-20 microscope equipped with a field-emission gun (operating at 200 kV). The transmission spectra of the films were recorded by the Shimadzu spectrophotometer (mode UV2450) for PL measurements were performed by a Horiba spectrofluorometer (Fluoromax-4). The wavelength of the excitation light source is 525 nm. XRD and TGA measurements were carried out on the D8 Advance (Bruker) and TG/DTG7300 (SII NanoTechnology), respectively. XPS and UPS were performed by the Escalab 250Xi (Thermo Fisher). The JV characteristics of devices were recorded from a programmable Keithley 2400 source meter under simulated AM 1.5G solar irradiation at 100 mW·cm−2 in air condition.

Availability of data and materials

All data supporting the conclusions of this article are included within the article and supplementary document.

Abbreviations

PSCs:

Perovskite solar cells

PCE:

Power conversion efficiency

ITO:

Indium tin oxide

HTLs:

Hole transport layers

Spiro-OMeTAD:

2,2′,7,7′-Tetrakis(N,N′-di-p-methoxyphenylamine)-9,9′-spirobiflurorene

MOFs:

Metal–organic frameworks

Ni3(HITP)2 :

Ni3(2,3,6,7,10,11-hexaiminotriphenylene)2

PL:

Steady-state photoluminescence

EQE:

External quantum efficiency

XRD:

X-ray diffraction

TEM:

Transmission electron microscope

XPS:

X-ray photoelectron spectroscopy

UPS:

Ultraviolet photoemission spectroscopy

E f :

Femi level

V B :

Valence band maximum

SEM:

Scanning electron microscopy

AFM:

Atomic force microscopy

RMS:

Root-mean-square

References

  1. Zheng X, Hou Y, Bao C, Yin J, Yuan F, Huang Z et al (2020) Managing grains and interfaces via ligand anchoring enables 22.3%-efficiency inverted perovskite solar cells. Nat Energy 5:131–140

    Article  CAS  Google Scholar 

  2. Jung EH, Jeon NJ, Park EY, Moon CS, Shin TJ, Yang TY et al (2019) Efficient, stable and scalable perovskite solar cells using poly(3-hexylthiophene). Nature 567:511–515

    Article  CAS  Google Scholar 

  3. Bai S, Da P, Li C, Wang Z, Yuan Z, Fu F et al (2019) Planar perovskite solar cells with long-term stability using ionic liquid additives. Nature 571:245–250

    Article  CAS  Google Scholar 

  4. Zhao D, Yu Y, Wang C, Liao W, Shrestha N, Grice CR et al (2017) Low-bandgap mixed tin–lead iodide perovskite absorbers with long carrier lifetimes for all-perovskite tandem solar cells. Nat Energy 2:17018

    Article  CAS  Google Scholar 

  5. Xu XL, Xiao LB, Zhao J, Pan BK, Li J, Liao WQ et al (2020) Molecular ferroelectrics-driven high-performance perovskite solar cells. Angew Chem Int Ed Engl 59:19974–19982

    Article  CAS  Google Scholar 

  6. Chen Y, Yang Z, Wang S, Zheng X, Wu Y, Yuan N et al (2018) Design of an inorganic mesoporous hole-transporting layer for highly efficient and stable inverted perovskite solar cells. Adv Mater 30:1805660

    Article  Google Scholar 

  7. Wang Y, Wu T, Barbaud J, Kong W, Cui D, Chen H et al (2019) Stabilizing heterostructures of soft perovskite semiconductors. Sci 365:687–691

    Article  CAS  Google Scholar 

  8. Wu R, Yao J, Wang S, Zhou X, Wang Q, Gao L et al (2019) Ultracompact, well-packed perovskite flat crystals: preparation and application in planar solar cells with high efficiency and humidity tolerance. ACS Appl Mater Interfaces 11:11283–11291

    Article  CAS  Google Scholar 

  9. Huang L, Zhou X, Xue R, Xu P, Wang S, Xu C et al (2020) Low-temperature growing anatase TiO2/SnO2 multi-dimensional heterojunctions at MXene conductive network for high-efficient perovskite solar cells. Nanomicro Lett 12:44

    CAS  Google Scholar 

  10. NREL, best research-cell efficiencies chart. https://www.nrel.gov/pv/cell-efficiency.html . Accessed Sept 2020

  11. Liu M, Johnston MB, Snaith HJ (2013) Efficient planar heterojunction perovskite solar cells by vapour deposition. Nature 501:395–398

    Article  CAS  Google Scholar 

  12. Haitao X, Feng Y, Dan Z, Xunfan L, Lie C, Yiwang C (2020) Hole transport layers for organic solar cells: recent progress and prospects. J Mater Chem A 8:11478–11492

    Article  Google Scholar 

  13. Wu T, Wang Z, Xiao L, Qin P, Qin Z, Ma L et al (2021) Mesoporous Au@Cu2−xS core-shell nanoparticles with double localized surface plasmon resonance and ligand modulation for hole-selective passivation in perovskite solar cells. Sol RRL 5:2100358

    Article  CAS  Google Scholar 

  14. Zheng Y, Ge B, Zheng LR, Hou Y, Yang S, Yang HG (2021) Solution-processable nickel–chromium ternary oxide as an efficient hole transport layer for inverted planar perovskite solar cells. J Mater Chem A 9:21792–21798

    Article  CAS  Google Scholar 

  15. Du Q, Shen Z, Chen C, Li F, Jin M, Li H et al (2021) Spiro-OMeTAD:Sb2S3 hole transport layer with triple functions of overcoming lithium salt aggregation, long-term high conductivity, and defect passivation for perovskite solar cells. Sol RRL 5:2100622

    Article  CAS  Google Scholar 

  16. Wang Z-K, Liao L-S (2018) Doped charge-transporting layers in planar perovskite solar cells. Adv Opt Mater 6:1800276

    Article  Google Scholar 

  17. Pham HD, Yang TCJ, Jain SM, Wilson GJ, Sonar P (2020) Development of dopant-free organic hole transporting materials for perovskite solar cells. Adv Energy Mater 10:1903326

    Article  CAS  Google Scholar 

  18. Ma Z, Xiao Z, Liu Q, Huang D, Zhou W, Jiang H et al (2020) Oxidization-free spiro-OMeTAD hole-transporting layer for efficient CsPbI2Br perovskite solar cells. ACS Appl Mater Interfaces 12:52779–52787

    Article  CAS  Google Scholar 

  19. Reza KM, Gurung A, Bahrami B, Mabrouk S, Elbohy H, Pathak R et al (2020) Tailored PEDOT:PSS hole transport layer for higher performance in perovskite solar cells: enhancement of electrical and optical properties with improved morphology. J Energy Chem 44:41–50

    Article  Google Scholar 

  20. Xu C, Liu Z, Lee E-C (2018) High-performance metal oxide-free inverted perovskite solar cells using poly(bis(4-phenyl)(2,4,6-trimethylphenyl)amine) as the hole transport layer. J Mater Chem C 6:6975–6981

    Article  CAS  Google Scholar 

  21. Wang X, Wu J, Yang Y, Liu X, Guo Q, Song Z et al (2019) High performance and stable perovskite solar cells using vanadic oxide as a dopant for spiro-OMeTAD. J Mater Chem A 7:13256–13264

    Article  CAS  Google Scholar 

  22. Cong S, Yang H, Lou Y, Han L, Yi Q, Wang H et al (2017) Organic small molecule as the underlayer toward high performance planar perovskite solar cells. ACS Appl Mater Interfaces 9:2295–2300

    Article  CAS  Google Scholar 

  23. Ryu S, Noh JH, Jeon NJ, Chan Kim Y, Yang WS, Seo J et al (2014) Voltage output of efficient perovskite solar cells with high open-circuit voltage and fill factor. Energy Environ Sci 7:2614–2618

    Article  CAS  Google Scholar 

  24. Stranks SD, Snaith HJ (2015) Metal-halide perovskites for photovoltaic and light-emitting devices. Nat Nanotechnol 10:391–402

    Article  CAS  Google Scholar 

  25. Lu H, Ma Y, Gu B, Tian W, Li L (2015) Identifying the optimum thickness of electron transport layers for highly efficient perovskite planar solar cells. J Mater Chem A 3:16445–16452

    Article  CAS  Google Scholar 

  26. Wang Y, Yue Y, Yang X, Han L (2018) Toward long-term stable and highly efficient perovskite solar cells via effective charge transporting materials. Adv Energy Mater 8:1800249

    Article  Google Scholar 

  27. Urieta-Mora J, Garcia-Benito I, Molina-Ontoria A, Martin N (2018) Hole transporting materials for perovskite solar cells: a chemical approach. Chem Soc Rev 47:8541–8571

    Article  CAS  Google Scholar 

  28. Lamberti F, Gatti T, Cescon E, Sorrentino R, Rizzo A, Menna E et al (2019) Evidence of Spiro-OMeTAD de-doping by tert-butylpyridine additive in hole-transporting layers for perovskite solar cells. Chem 5:1806–1817

    Article  CAS  Google Scholar 

  29. Zhang L, Jiang C, Wu C, Ju H, Jiang G, Liu W et al (2018) V2O5 as hole transporting material for efficient all inorganic Sb2S3 solar cells. ACS Appl Mater Interfaces 10:27098–27105

    Article  CAS  Google Scholar 

  30. Zuo C, Ding L (2015) Solution-processed Cu2O and CuO as hole transport materials for efficient perovskite solar cells. Small 11:5528–5532

    Article  CAS  Google Scholar 

  31. Schulz P, Tiepelt JO, Christians JA, Levine I, Edri E, Sanehira EM et al (2016) High-work-function molybdenum oxide hole extraction contacts in hybrid organic-inorganic perovskite solar cells. ACS Appl Mater Interfaces 8:31491–31499

    Article  CAS  Google Scholar 

  32. Ye S, Sun W, Li Y, Yan W, Peng H, Bian Z et al (2015) CuSCN-based inverted planar perovskite solar cell with an average PCE of 15.6%. Nano Lett 15:3723–3728

    Article  CAS  Google Scholar 

  33. You J, Meng L, Song TB, Guo TF, Yang YM, Chang WH et al (2016) Improved air stability of perovskite solar cells via solution-processed metal oxide transport layers. Nat Nanotechnol 11:75–81

    Article  Google Scholar 

  34. Fakharuddin A, Vasilopoulou M, Soultati A, Haider MI, Briscoe J, Fotopoulos V et al (2021) Robust inorganic hole transport materials for organic and perovskite solar cells: insights into materials electronic properties and device performance. Sol RRL 5:2000555

    Article  CAS  Google Scholar 

  35. Yang X, Lin X, Zhao YS, Yan D (2018) Recent advances in micro-/nanostructured metal–organic frameworks towards photonic and electronic applications. Chemistry 24:6484–6493

    Article  CAS  Google Scholar 

  36. Da-Wei F, Wen Z, Hong-Ling C, Yi Z, Jia-Zhen G, Ren-Gen X et al (2011) A multiferroic perdeutero metal–organic framework†. Angew Chem 123:12153–12157

    Article  Google Scholar 

  37. Shah BB, Kundu T, Zhao D (2019) Mechanical properties of shaped metal–organic frameworks. Top Curr Chem (Cham) 377(5):25

    Article  Google Scholar 

  38. Xu Y, Li Q, Xue H, Pang H (2018) Metal–organic frameworks for direct electrochemical applications. Coord Chem Rev 376:292–318

    Article  CAS  Google Scholar 

  39. Usman M, Mendiratta S, Lu KL (2017) Semiconductor metal–organic frameworks: future low-bandgap materials. Adv Mater 29:1605071

    Article  Google Scholar 

  40. Huang T, Lou Z, Lu Y, Li R, Jiang Y, Shen G et al (2019) Metal–organic-framework-derived MCo2O4 (M=Mn and Zn) nanosheet arrays on carbon cloth as integrated anodes for energy storage applications. ChemElectroChem 6:5836–5843

    Article  CAS  Google Scholar 

  41. Allendorf MD, Dong R, Feng X, Kaskel S, Matoga D, Stavila V (2020) Electronic devices using open framework materials. Chem Rev 120:8581–8640

    Article  CAS  Google Scholar 

  42. Allendorf MD, Schwartzberg A, Stavila V, Talin AA (2011) A roadmap to implementing metal–organic frameworks in electronic devices: challenges and critical directions. Chemistry 17:11372–11388

    Article  CAS  Google Scholar 

  43. Tong P, Liang J, Jiang X, Li J (2020) Research progress on metal–organic framework composites in chemical sensors. Crit Rev Anal Chem 50:376–392

    Article  CAS  Google Scholar 

  44. Furukawa H, Cordova KE, O’Keeffe M, Yaghi OM (2013) The chemistry and applications of metal–organic frameworks. Sci 341:1230444

    Article  Google Scholar 

  45. Ferey G (2008) Hybrid porous solids: past, present, future. Chem Soc Rev 37:191–214

    Article  CAS  Google Scholar 

  46. Shen M, Zhang Y, Xu H, Ma H (2021) MOFs based on the application and challenges of perovskite solar cells. iScience 24:103069

    Article  Google Scholar 

  47. Heo DY, Do HH, Ahn SH, Kim SY (2020) Metal–organic framework materials for perovskite solar cells. Polymers (Basel) 12:2061

    Article  CAS  Google Scholar 

  48. Huang L, Zhou X, Wu R, Shi C, Xue R, Zou J et al (2019) Oriented haloing metal–organic framework providing high efficiency and high moisture-resistance for perovskite solar cells. J Power Sources 433:226699

    Article  CAS  Google Scholar 

  49. Vinogradov AV, Zaake-Hertling H, Hey-Hawkins E, Agafonov AV, Seisenbaeva GA, Kessler VG et al (2014) The first depleted heterojunction TiO2-MOF-based solar cell. Chem Commun (Camb) 50:10210–10213

    Article  CAS  Google Scholar 

  50. Chang TH, Kung CW, Chen HW, Huang TY, Kao SY, Lu HC et al (2015) Planar heterojunction perovskite solar cells incorporating metal–organic framework nanocrystals. Adv Mater 27:7229–7235

    Article  CAS  Google Scholar 

  51. Shen D, Pang A, Li Y, Dou J, Wei M (2018) Metal–organic frameworks at interfaces of hybrid perovskite solar cells for enhanced photovoltaic properties. Chem Commun (Camb) 54:1253–1256

    Article  CAS  Google Scholar 

  52. Li M, Xia D, Yang Y, Du X, Dong G, Jiang A et al (2018) Doping of In-2(phen)(3)Cl-6 center dot CH3CN center dot 2H(2)O indium-based metal–organic framework into hole transport layer for enhancing perovskite solar cell efficiencies. Adv Energy Mater 8:1702052

    Article  Google Scholar 

  53. Ryu U, Jee S, Park JS, Han IK, Lee JH, Park M et al (2018) Nanocrystalline titanium metal–organic frameworks for highly efficient and flexible perovskite solar cells. ACS Nano 12:4968–4975

    Article  CAS  Google Scholar 

  54. Wu G, Huang J, Zang Y, He J, Xu G (2017) Porous field-effect transistors based on a semiconductive metal–organic framework. J Am Chem Soc 139:1360–1363

    Article  CAS  Google Scholar 

  55. Sun L, Liao B, Sheberla D, Kraemer D, Zhou J, Stach EA et al (2017) A microporous and naturally nanostructured thermoelectric metal–organic framework with ultralow thermal conductivity. Joule 1:168–177

    Article  CAS  Google Scholar 

  56. Kim G-W, Lee J, Kang G, Kim T, Park T (2018) Donor-acceptor type dopant-free, polymeric hole transport material for planar perovskite solar cells (19.8%). Adv Energy Mater 8:1701935

    Article  Google Scholar 

  57. Han L, Cong S, Yang H, Lou Y, Wang H, Huang J et al (2018) Environmental-friendly urea additive induced large perovskite grains for high performance inverted solar cells. Sol RRL 2:1800054

    Article  Google Scholar 

  58. Shang R, Zhou Z, Nishioka H, Halim H, Furukawa S, Takei I et al (2018) Disodium benzodipyrrole sulfonate as neutral hole-transporting materials for perovskite solar cells. J Am Chem Soc 140:5018–5022

    Article  CAS  Google Scholar 

Download references

Acknowledgements

We gratefully acknowledge the support from the Priority Academic Program Development (PADA) of Jiangsu Higher Education Institutions for Optical Engineering, the Key Lab of Advanced Optical Manufacturing Technologies of Jiangsu Province and Key Lab of Modern Optical Technologies of Education Ministry of China in Soochow University, and Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering in Changzhou University.

Funding

Not applicable.

Author information

Authors and Affiliations

Authors

Contributions

GZ and YL conceived the research project. CS completed the synthesis of the MOFs materials under the supervision of GX. CS, RW, and WY performed the experiments of the devices and wrote the paper under the supervision of GZ and YL. KC, SD, JW, FY, and CP provided valuable discussion. All authors read and approved the final manuscript.

Corresponding authors

Correspondence to Yanhui Lou, Gang Xu or Guifu Zou.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary Information

Additional file 1: Figure S1

. Illustration of the assembly process for the Ni3(HITP)2 film. Figure S2. EDX mapping of the Ni3(HITP)2 membranes. Figure S3. XPS spectra of the Ni3(HITP)2 membranes. Figure S4. AFM images of different thicknesses of Ni3(HITP)2 membranes. Figure S5. Photographs of the bare ITO glass and with different thicknesses of Ni3(HITP)2 membranes. Figure S6. Steady-state PL spectra of perovskite/ITO based on 20 nm, 30 nm, 40 nm, and 50 nm Ni3(HITP)2 film and PEDOT/PSS; Inset: the enlarged steady-state PL spectra of perovskite on the 20 nm and 30 nm Ni3(HITP)2 film repeated by three times, respectively. Figure S7. Time-resolved PL spectra of perovskite on the ITO substrate with different thicknesses of Ni3(HITP)2 film and PEDOT/PSS. Figure S8. AFM images of different thicknesses of Ni3(HITP)2 membranes. Figure S9. XRD pattern of perovskite films deposition on different thicknesses of Ni3(HITP)2 membranes. Table S1. The average decay lifetimes of the perovskite/ITO with different hole transport layers.

Rights and permissions

Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Wang, R., Yu, W., Sun, C. et al. High-Hole-Mobility Metal–Organic Framework as Dopant-Free Hole Transport Layer for Perovskite Solar Cells. Nanoscale Res Lett 17, 6 (2022). https://doi.org/10.1186/s11671-021-03643-7

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: https://doi.org/10.1186/s11671-021-03643-7

Keywords

  • Dopant-free hole transport materials
  • Metal–organic frameworks
  • Perovskite solar cells
  • High hole mobility
  • Ni3(2,3,6,7,10,11-hexaiminotriphenylene)2