The effect of dopant and optical micro-cavity on the photoluminescence of Mn-doped ZnSe nanobelts
© Zhou et al.; licensee Springer. 2013
Received: 14 May 2013
Accepted: 7 June 2013
Published: 5 July 2013
Pure and Mn-doped ZnSe nanobelts were synthesized by a convenient thermal evaporation method. Scanning electron microscopy, X-ray powder diffraction, energy dispersive X-ray spectroscopy and corresponding element mapping, and transmission electron microscope were used to examine the morphology, phase structure, crystallinity, composition, and growth direction of as-prepared nanobelts. Raman spectra were used to confirm the effective doping of Mn2+ into ZnSe nanobelts. Micro-photoluminescence (PL) spectra were used to investigate the emission property of as-prepared samples. A dominant trapped-state emission band is observed in single ZnSe Mn nanobelt. However, we cannot observe the transition emission of Mn ion in this ZnSeMn nanobelt, which confirm that Mn powder act as poor dopant. There are weak near-bandgap emission and strong 4T1 → 6A1 transition emission of Mn2+ in single and nanobelt. More interesting, the 4T1 → 6A1 transition emission in nanobelt split into multi-bands. PL mapping of individual splitted sub-bands were carried out to explore the origin of multi-bands. These doped nanobelts with novel multi-bands emission can find application in frequency convertor and wavelength-tunable light emission devices.
KeywordsMn dopant ZnSe nanobelts Optical micro-cavity Photoluminescence
Recently, doped one-dimension (1D) semiconductor nanostructures are especially attractive for their excellent and unique optical and optoelectronic properties [1, 2], which were affected greatly by optical micro-cavity and dopant. 1D nanostructures doped with transition metal (such as Cr, Mn, Fe, Co, and Ni), which can find extensive application in spintronics and nanophotonics [3–5], show novel emission and interesting magnetic transport properties. For example, single crystalline Ga0.95Mn0.05As nanowires show temperature-dependent hopping conduction . Cu-doped Cd0.84Zn0.16S nanoribbons show four orders of magnitude larger photocurrent than the undoped ones, demonstrating potential application in photoconductors and chemical sensors . The emission of transition metal ion has specific wavelength, such as the emission of manganese (Mn) ion which is located generally at 585 nm. Moreover, 1D nanostructures can confine the coherent transport or transmission of photon to the definite direction, that is, 1D nanostructures can form optical micro-cavity easily and work as effective optical waveguide within a nanometer scale . Recently, there is an increasing research interest on the optical micro-cavity and corresponding multi-mode emission spectra in doped 1D nanostructures . Zou et al. observed multi-mode emission from doped ZnO nanowires due to F-P cavity effect . Multi-mode emission was also observed in In x Ga1 - xN superlattice . Except for the inorganic semiconductor nanostructures, organic nanofibers can also act as coherent random laser with multi-mode emission . Recent research shows that the formation of multi-intracavities plays an important role in the multi-mode emission . These multi-intracavities can couple to produce coherent emission. These confined cavities and multi-band emission of 1D nanostructures are affected strongly by synthesis parameter and deliberate doping. The optical properties of 1D nanostructures are sensitive to minute change of crystal quality, crystal defect, and dopant. The latter can introduce defect state and is therefore very important. So, it is necessary to investigate the direct correlation between dopant and optical properties within the nanometer scale.
ZnSe, a direct semiconductor with a bandgap of 2.63 eV at room temperature, shows excellent optical properties and potential application in light emitting diode and laser diode. 1D ZnSe nanostructures possess novel light emission property . Recently, Vugt et al. observed the novel light-matter interaction in ZnSe nanowires, which can be used to tailor waveguide dispersion and speed of propagating light . In this paper, we synthesize three Mn-ZnSe nanobelts using different dopant compounds. Transmission electron microscopy (TEM) and scanning near-field optical microscopy (SNOM) techniques were used to provide simultaneous investigation on the micro-structure and crystallinity, micro-PL spectrum, and mode-selected mapping image. Both near-bandgap emission and trapped-state emission of ZnSe are observed in Mn-ZnSe nanobelts obtained using Mn powder as dopant. However, the Mn ion transition emission cannot be observed in this ZnSeMn nanobelt. Using manganese chloride (MnCl2) as dopant, strong Mn ion transition emission and weak near-bandgap emission are observed. We can also observe the strong Mn ion transition emission and weak near-bandgap emission in the Mn-ZnSe nanobelts obtained using manganese acetate as dopant. More interestingly, the Mn ion transition emission can split into multi-mode emission due to multi-Fabry-Pérot cavity effect in the nanobelt. Raman spectrum was used to confirm the effective doping. These results are helpful in understanding the effect of dopant on the optical micro-cavities and multi-mode emission. These Mn-ZnSe nanostructures can find promising applications in multicolor emitter or wavelength selective photodetector.
The 1D Mn-ZnSe nanobelts were synthesized by a simple thermal evaporation method. Commercial grade mixed powder of ZnSe and Mn or MnCl2 or manganese acetate (Mn(CH3COO)2) with a weight ratio of 5:1 was used as source material. The obtained samples were labeled as ZnSeMn, , , respectively. The other synthesis processes are similar with our previous report . The evaporation temperature, growth temperature, and growth time are set to 900°C, 600°C, and 45 min, respectively. A yellow product deposited on the silicon wafer after the furnace cools down to room temperature. For comparison, the pure ZnSe nanobelts were also synthesized using ZnSe powder as source material.
XRD (D/max-5000, Rigaku Corporation, Tokyo, Japan), E-SEM (QUANTA 200, FEI, Hillsboro, OR, USA), energy dispersive X-ray spectroscopy (EDS; attached to SEM), and TEM (JEM-3010, JEOL Ltd., Tokyo, Japan) were used to examine the phase structure, crystallinity, and composition of the as-prepared nanobelts. Raman spectroscopy was performed in a confocal microscope (LABRAM-010, HORIBA Ltd., Kyoto, Japan) using He-Ne laser (632.8 nm) as excitation light source. The PL and corresponding mapping were obtained by SNOM (alpha 300 series, WITec GmbH, Ulm, Germany) with He-Cd laser (325 nm) as excitation source at room temperature. In all optical experiments, the excitation signal illuminated perpendicularly onto the sample surface.
Results and discussion
We synthesized pure and Mn-doped ZnSe nanobelts successfully using thermal evaporation method. Mn can dope effectively into ZnSe crystal when MnCl2 or Mn(CH3COO)2 were used as dopants in the source material. EDS mapping indicates that the distribution of Mn is inhomogeneous in the nanobelt. All of these doped nanobelts grew along the <111> direction. HRTEM demonstrates that there are a lot of defect states in the nanobelt. Raman spectra confirm that Mn2+ was doped into and nanobelts successfully. The optical properties are affected strongly by the concentration and spatial distribution of the dopant. Optical micro-cavity also plays an important role to the emission property. Nanobelt shows strong 4T1 → 6A1 transition emission of Mn2+. However, the 4T1 → 6A1 transition emission of Mn2+ in nanobelt splits into many narrow sub-bands due to the formation of integrated multi-Fabry-Pérot cavities, which can couple to produce coherent emission with selected wavelength and cavity mode. PL mapping confirms that there are several micro-cavities in the single nanobelt. Such doped nanobelts with integrated multi-micro-cavities and modulated emission wavelength can be optimized to fabricate nanophotonic devices and quantum coherent modulators.
WZ got his PhD degree in 2010. He is an assistant professor now. RL is an associate professor. DT and BZ are professors.
We thank the NSF of China (term nos.: 51102091, 91121010, 90606001, and 20873039), Research Fund for the Doctoral Program of Higher Education of China (no.: 20114306120003), Program for Changjiang Scholars and Innovative Research Team in University (PCSIRT, no.: IRT0964), and Hunan Provincial Natural Science Foundation (11JJ7001) for the financial support.
- Liu C, Sun JW, Tang JY, Yang PD: Zn-doped p-type gallium phosphide nanowire photocathodes from a surfactant-free solution synthesis. Nano Lett 2012, 12: 5407–5411. 10.1021/nl3028729View Article
- Nie B, Luo LB, Chen JJ, Hu JG, Wu CY, Wang L, Yu YQ, Zhu ZF, Jie JS: Fabrication of p-type ZnSe:Sb nanowires for high-performance ultraviolet light photodetector application. Nanotechnology 2013, 24: 095603. 10.1088/0957-4484/24/9/095603View Article
- Zeng YJ, Pereira LMC, Menghini M, Temst K, Vantomme A, Locquet JP, Haesendonck CV: Tuning quantum corrections and magnetoresistance in ZnO nanowires by ion implantation. Nano Lett 2012, 12: 666–672. 10.1021/nl2034656View Article
- Feng GY, Yang C, Zhou SH: Nanocrystalline Cr2+-doped ZnSe nanowires laser. Nano Lett 2013, 13: 272–275. 10.1021/nl304066hView Article
- López I, Nogales E, Méndez B, Javier P: Influence of Sn and Cr doping on morphology and luminescence of thermally grown Ga2O3 nanowires. J Phys Chem C 2013, 117: 3036–3045. 10.1021/jp3093989View Article
- Paschoal W Jr, Kumar S, Borschel C, Wu P, Canali CM, Ronning C, Samuelson L, Pettersson H: Hopping conduction in Mn ion-implanted GaAs nanowires. Nano Lett 2012, 12: 4838–4842. 10.1021/nl302318fView Article
- Lui TY, Zapien JA, Tang H, Ma DDD, Liu YK, Lee CS, Lee ST, Shi SL, Xu SJ: Photoluminescence and photoconductivity properties of copper-doped Cd1-xZn x S nanoribbons. Nanotechnology 2006, 17: 5935. 10.1088/0957-4484/17/24/006View Article
- Huang MH, Mao S, Feick H, Yan HQ, Wu YY, Kind H, Weber E, Russo R, Yang PD: Room-temperature ultraviolet nanowire nanolasers. Science 2001, 292: 1897–1899. 10.1126/science.1060367View Article
- Pauzauskie PJ, Yang PD: Nanowire photonics. Mater Today 2006, 9: 36–45.View Article
- Zou BS, Liu RB, Wang FF, Pan AL, Cao L, Wang ZL: Lasing mechanism of ZnO nanowires/nanobelts at room temperature. J Phys Chem B 2006, 110: 12865–12873. 10.1021/jp061357dView Article
- Qian F, Li Y, Gradecak S, Park HG, Dong Y, Ding Y, Wang ZL, Lieber CM: Multi-quantum-well nanowire heterostructures for wavelength-controlled lasers. Nature Mater 2008, 7: 701–706. 10.1038/nmat2253View Article
- Quochi F: Random lasers based on organic epitaxial nanofibers. J Opt 2010, 12: 024003. 10.1088/2040-8978/12/2/024003View Article
- Li Y, Dai GZ, Zhou CJ, Zhang QL, Wan Q, Fu LM, Zhang JP, Liu RB, Cao CB, Pan AL, Zhang YH, Zou BS: Formation and optical properties of ZnO:ZnFe2O4 superlattice microwires. Nano Res 2010, 3: 326–338. 10.1007/s12274-010-1036-yView Article
- Saxena A, Yang SX, Philipose U, Ruda HE: Excitonic and pair-related photoluminescence in ZnSe nanowires. J Appl Phys 2008, 103: 053109. 10.1063/1.2885729View Article
- Vugt LK, Zhang B, Piccione B, Spector AA, Agarwal R: Size-dependent waveguide dispersion in nanowire optical cavities: slowed light and dispersionless guiding. Nano Lett 2009, 9: 1684–1688. 10.1021/nl900371rView Article
- Zhou WC, Liu RB, Tang DS, Wang XX, Fan HM, Pan AL, Zhang QL, Wan Q, Zou BS: Luminescence and local photonic confinement of single ZnSe:Mn nanostructure and the shape dependent lasing behavior. Nanotechnology 2013, 24: 055201. 10.1088/0957-4484/24/5/055201View Article
- Lee JY, Kim DS, Kang JH, Yoon SW, Lee H, Park J: Novel Zn1-xMn x Se ( x =0.1–0.4) one-dimensional nanostructures: nanowires, zigzagged nanobelts, and toothed nanosaws. J Phys Chem B 2006, 110: 25869–25874. 10.1021/jp065749wView Article
- Kang JW, Choi YS, Choe M, Kim NY, Lee T, Kim BJ, Tu CW, Park SJ: Electrical and structural properties of antimony-doped p-type ZnO nanorods with self-corrugated surfaces. Nanotechnology 2012, 23: 495712. 10.1088/0957-4484/23/49/495712View Article
- Suh M, Meyyappan M, Ju S: The effect of Ga content on In2xGa2–2xO3 nanowire transistor characteristics. Nanotechnology 2012, 23: 305203. 10.1088/0957-4484/23/30/305203View Article
- Wang FF, Zhang ZH, Liu RB, Wang X, Zhu X, Pan AL, Zou BS: Structure and stimulated emission of ZnSe nanoribbons grown by thermal evaporation. Nanotechnology 2007, 18: 305705. 10.1088/0957-4484/18/30/305705View Article
- Popović ZV, Milutinović A: Far-infrared reflectivity and Raman scattering study of α -MnSe. Phys Rev B 2006, 73: 155203.View Article
- Jiang Y, Meng XM, Yiu WC, Liu J, Ding JX, Lee CS, Lee ST: Zinc selenide nanoribbons and nanowires. J Phys Chem B 2004, 108: 2784–2787. 10.1021/jp035595+View Article
- Leung YP, Wallace CHC, Markov I, Pang GKH, Ong HC, Yuk TI: Synthesis of wurtzite ZnSe nanorings by thermal evaporation. Appl Phys Lett 2006, 88: 183110. 10.1063/1.2200155View Article
- Philipose U, Xu T, Yang S, Sun P, Ruda HE, Wang YQ, Kavanagh KL: Enhancement of band edge luminescence in ZnSe nanowires. J Appl Phys 2006, 100: 084316. 10.1063/1.2362930View Article
- Panda AB, Acharya S, Efrima S: Ultranarrow ZnSe nanorods and nanowires: structure, spectroscopy, and one-dimensional properties. Adv Mater 2005, 17: 2471–2474. 10.1002/adma.200500551View Article
- Na CW, Han DS, Kim DS, Kang YJ, Lee JY, Park J, Oh DK, Kim KS, Kim D: Photoluminescence of Cd1-xMn x S ( x ≤0.3) nanowires. J Phys Chem B 2006, 110: 6699–6704. 10.1021/jp060224pView Article
- Chen W, Sammynaiken R, Huang Y, Malm JO, Wallenberg R, Bovin JO, Zwiller V, Kotov NA: Crystal field, phonon coupling and emission shift of Mn2+ in ZnS:Mn nanoparticles. J Appl Phys 2001, 89: 1120. 10.1063/1.1332795View Article
- Liu QH, Sun ZH, Yan WS, Zhong WJ, Pan ZY, Hao LY, Wei SQ: Anomalous magnetic behavior of Mn-Mn dimers in the dilute magnetic semiconductor (Ga, Mn)N. Phys Rev B 2007, 76: 245210.View Article
- Pradhan N, Peng XG: Efficient and color-tunable Mn-doped ZnSe nanocrystal emitters: control of optical performance via greener synthetic chemistry. J Am Chem Soc 2007, 129: 3339–3347. 10.1021/ja068360vView Article
- Goede O, Thong DD: Energy transfer processes in (Zn, Mn)S mixed crystals. Phys Status Solidi B 1984, 124: 343–353. 10.1002/pssb.2221240137View Article
- Kim DS, Cho YJ, Park J, Yoon J, Jo Y, Jung MH: (Mn, Zn) Co-doped CdS nanowires. J Phys Chem C 2007, 111: 10861–10868.View Article
- Barglik-Chory C, Remenyi C, Dem C, Schmitt M, Kiefer W, Gould C, Rüster C, Schmidt G, Hofmann DM, Pfistererd D, Müller G: Synthesis and characterization of manganese-doped CdS nanoparticles. Phys Chem Chem Phys 2003, 5: 1639–1643. 10.1039/b300343dView Article
- Vugt LKV, Rühle S, Ravindran P, Gerritsen HC, Kuipers L, Vanmaekelbergh D: Exciton polaritons confined in a ZnO nanowire cavity. Phys Rev Lett 2006, 97: 147401.View Article
This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.