- Nano Express
- Open Access
Preparing of Highly Conductive Patterns on Flexible Substrates by Screen Printing of Silver Nanoparticles with Different Size Distribution
© The Author(s). 2016
- Received: 4 August 2016
- Accepted: 14 September 2016
- Published: 20 September 2016
A facile one-step polyol method is employed to synthesize the Ag nanoparticles (NPs) in large scale. The Ag NPs with different average diameter (from 52 to 120 nm) and particle size distribution are prepared by changing the mass ratio of AgNO3 and PVP. Furthermore, the as-obtained Ag NPs are prepared as conductive inks, which could be screen printed on various flexible substrates and formed as conductive patterns after sintering treatment. During the reaction process, PVP is used as the capping reagent for preventing the agglomeration of Ag NPs, and the influence of the mass ratio of AgNO3 and PVP to the size distribution of Ag NPs is investigated. The results of electronic properties reveal that the conductivity of printed patterns is highly dependent on the size distribution of as-obtained Ag NPs. Among all the samples, the optimal conductivity is obtained when the mass ratio of AgNO3 and PVP is 1:0.4. Subsequently, the sintering time and temperature are further investigated for obtaining the best conductivity; the optimal electrical resistivity value of 3.83 μΩ · cm is achieved at 160 °C for 75 min, which is close to the resistivity value of the bulk silver (1.58 μΩ · cm). Significantly, there are many potential advantages in printed electronics applications because of the as-synthesized Ag NPs with a low sintering temperature and low electrical resistivity.
- Ag nanoparticles
- Size distribution
- Electrical resistivity
- Screen printing
- Printed electronics
Printed electronics represents a promising research field for flexible electronics because of the advantages of mass production, low cost, and environment friendly, which receives growing interesting in recent years [1–5]. Various printing technologies are proposed to facilitate more rapid development of printed electronics, such as inkjet printing, gravure printing, offset printing, and screen printing, etc [6–12]. Among them, screen printing route is often considered as the most suitable candidate for printed electronics because of its intrinsic simplicity, affordability, high speed, mass production capability, and versatility . Moreover, the screen printing is also a popular technique for printing on various rigid or flexible substrates . It is noteworthy that the conductive ink is the critical factor to fabricate the desired patterns with required conductivity and quality in screen-printed electronics [1, 15]. Recently, many nanomaterials are developed and used as conductive inks, including metallic nanoparticles (NPs), conductive polymers , graphene , carbon nanotube (CNT) [18, 19], etc. . The conductive polymers, graphene, and CNT as conductive ink are widely used to print integrated circuits . However, the conductivity of such inks still has a room to improve and elevate . Therefore, ink formulations based on metallic NPs are selected as the strong candidate because of its desirable conductivity [23–25]. Currently, silver is the most reported material for conductive ink and also the most utilized in industrial applications.
It has been reported that the average diameter and particle size distribution of nanomaterials are closely related to the properties, such as optical, magnetic, and electronic properties [26–29]. For example, Jiang and co-workers prepared Ag NPs with various sizes by citrate reduction method. When the size of the Ag NPs is decreased, the corresponding photoluminescence spectra shifted to higher energies, which reveal that the optical property of Ag NPs is dependent on particle size . However, the relationship between the size distribution and the electrical properties of the synthetic Ag NPs is rarely studied in detail, especially in printed patterns and printed devices.
Additionally, the use of Ag NP-based inks requires post-print sintering of the printed layers to form electrically networks and high conductive layers, and the sintering step can remove the organic component of inks [31, 32]. For example, Lee and co-workers printed Ag NP-based pastes with 50–100 nm in size on alumina substrates by screen printing, the optimal electrical resistivity of the film is 4.11 μΩ · cm when the printed film was sintered at 450 °C for 15 min . The obtained value of electrical resistivity may be compatible for various electronic devices, but the high sintering temperature of 450 °C is not useful for flexible printed electronics. This is because most of flexible substrates (such as paper, polyethylene terephthalate (PET), and polyvinyl chloride (PVC)) cannot resist to this high sintering temperature [34–36]. Cho and co-workers printed silver lines by screen printing with size around 20-nm Ag NPs and then a low temperature of 200 °C was chosen to sinter for 1 h. The lowest resistivity value of the synthesized inks is 33 μΩ · cm . The sintering temperature is low enough for flexible substrates, but the resistivity values of the synthesized inks still need to improve . Obviously, the improvement of electrical property at low sintering temperature is the eventual purpose for the as-synthesized Ag NP-based inks.
Herein, the Ag NPs with different size distribution are prepared through a one-step, high-effect, and high-reliability polyol method. The relationship between the size distribution and the electronics properties of printed Ag NPs layers are demonstrated. Furthermore, in order to obtaining high conductivity, the different sintering temperature and time of these final Ag NP-based patterns are further studied. Then, the SEM technique is applied to investigate the sintering mechanism of the as-prepared designed patterns.
Materials and Chemicals
Silver nitrate (AgNO3, 99.0 %), anhydrous alcohol (CH3CH2OH), and ethylene glycol (EG, 99.0 %) were purchased from Sinopharm Chemical Reagent Co., Ltd. Polyvinylpyrrolidone (PVP, MW = 10,000) was purchased from Aladdin Chemistry Co., Ltd. All chemicals were analytical grade and used as received without further purification. The high temperature-resistant PET (~210 °C, the thickness is 0.3 mm) and A4 paper were used as flexible substrates. Deionized water got from a Millipore system (ρ = 18.2 MΩ) was used in through experiments.
Synthesis of Ag NPs
The Ag NPs are prepared by the reduction of AgNO3 in EG solution in the presence of PVP. Typically, 0.531 g of AgNO3 and 0.531 g of PVP were dissolved in 25 mL of EG. Then, the mixture was heated up to 120 °C in an oil bath with vigorous magnetic stirring for 30 min. The obtained products were centrifuged at 12,000 rpm for 5 min and washed several times by ethanol. The Ag NPs with different morphology and size distribution are adjusted by the mass ratio of AgNO3 and PVP, which are named as S1–S6, respectively. Finally, the as-obtained Ag NPs were re-dispersed in ethanol for further characterization and application.
Deposition of Ag NP-Based Conductive Inks on PET Substrate
The Ag NP-based conductive inks were prepared by directly dispersing in ethanol, the weight percentage of Ag NP-based conductive inks is ca. 70 %, and deposited on the PET substrates. Finally, the patterns were sintered at 160 °C for 75 min in a drying oven. Additionally, different kinds of patterns including arrays, lines, and tags are screen printed. Here, the mesh count of the used screen printing plates is 300 fibers per centimeter. During the screen printing process, the as-prepared Ag inks are through the screen mesh and transferred to substrate under the pressure of squeegee.
The morphology analysis of the as-synthesized Ag NPs and the printed patterns were performed with a field emission scanning electron micrograph (FE-SEM) (Hitachi S-4800). The ultraviolet-visible (UV-vis) absorption spectra were recorded on a Shimadzu 2550 spectrophotometer. The X-ray diffraction (XRD) patterns of the samples were characterized on an X-ray diffractometer (PANalytical X’Pert Pro) with Cu Kα radiation operated at 40 kV and 40 mA at a scan rate of 0.05° 2θ s−1.
Electrical Performance Test
In this study, through a facile and one-step polyol method to synthesize the Ag NPs with different size distribution, the results of broad size distribution that contribute to the improvement of conductivity were found. The optimal electrical resistivity of 3.83 μΩ · cm was achieved by heat treatment at 160 °C for 75 min, and the electrical resistivity of as-obtained Ag inks is very close to the electrical resistivity of the bulk silver. The present results suggest possible applications in flexible printed electronics.
This work reported in this paper was financially supported by the NSFC (51171132), China Postdoctoral Science Foundation (2014M550406), Hubei Provincial Natural Science Foundation (2014CFB261), Natural Science Foundation of Jiangsu Province (BK20160383), Basic Research Plan Program of Shenzhen City, Fundamental Research Funds for the Central Universities (No. 2042015kf0184), and Wuhan University.
JD completed all the experiments and wrote the manuscript. JL, QYT, WJY, LL, and ZGD assisted with the manuscript preparation. ZHW revised the manuscript. WW conceived the study, revised the manuscript, and supervised the work. All authors read and approved the final manuscript.
The authors declare that they have no competing interests.
Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.
- Ren H-M, Guo Y, Huang S-Y, Zhang K, Yuen MM, Fu X-Z, Yu S, Sun R, Wong C-P (2015) ACS Appl Mater Interfaces 7:13685–13692View ArticleGoogle Scholar
- Ahn BY, Duoss EB, Motala MJ, Guo X, Park S-I, Xiong Y, Yoon J, Nuzzo RG, Rogers JA, Lewis JA (2009) Science 323:1590–1593View ArticleGoogle Scholar
- Kim C, Nogi M, Suganuma K, Yamato Y (2012) ACS Appl Mater Interfaces 4:2168–2173View ArticleGoogle Scholar
- Wang B-Y, Yoo T-H, Song Y-W, Lim D-S, Oh Y-J (2013) ACS Appl Mater Interfaces 5:4113–4119Google Scholar
- Yang C, Wong CP, Yuen MM, Mater J (2013) Chem C 1:4052–4069Google Scholar
- Farraj Y, Grouchko M, Magdassi S (2015) Chem Commun 51:1587–1590View ArticleGoogle Scholar
- Yu Y, Yan C, Zheng Z (2014) Adv Mater 26:5508–5516View ArticleGoogle Scholar
- Kwon J, Cho H, Eom H, Lee H, Suh YD, Moon H, Shin J, Hong S, Ko SH (2016) ACS Appl Mater Interfaces 8:11575–11582View ArticleGoogle Scholar
- Kwon J, Hong S, Suh YD, Yeo J, So HM, Chang WS, Ko SH (2015) ECS J Solid State Sc 4:3052–P3056View ArticleGoogle Scholar
- Lee H, Hong S, Kwon J, Suh YD, Lee J, Moon H, Yeo J, Ko SH (2015) J Mater Chem A 3:8339–8345View ArticleGoogle Scholar
- Shen W, Zhang X, Huang Q, Xu Q, Song W (2014) Nanoscale 6:1622–1628View ArticleGoogle Scholar
- Kang JS, Ryu J, Kim HS, Hahn HT (2011) J Electron Mater 40:2268–2277View ArticleGoogle Scholar
- Kazani I, Hertleer C, De Mey G, Schwarz A, Guxho G, Van Langenhove L (2012) Fibres Text East Eur 20:57–63Google Scholar
- Yafia M, Shukla S, Najjaran H (2015) J Micromechan Microeng 25:057001View ArticleGoogle Scholar
- Kamyshny A, Steinke J, Magdass S (2011) Open Appl Phys J 4:19–36View ArticleGoogle Scholar
- Xiong Z, Liu C (2012) Org Electron 13:1532–1540View ArticleGoogle Scholar
- Secor EB, Prabhumirashi PL, Puntambekar K, Geier ML, Hersam MC (2013) J Phys Chem Lett 4:1347–1351View ArticleGoogle Scholar
- Glatzel S, Schnepp Z, Giordano C (2013) Angew Chem Int Ed 52:2355–2358View ArticleGoogle Scholar
- Pidcock GC (2012) Adv Funct Mater 22:4790–4800View ArticleGoogle Scholar
- Cui SY, Liu J, Wu W (2015) Prog Chem 27:1509–1522Google Scholar
- Petukhov DI, Kirikova MN, Bessonov AA, Bailey MJ (2014) Mater Lett 132:302–306View ArticleGoogle Scholar
- Jung I, Jo YH, Kim I, Lee HM (2012) J Electron Mater 41:115–121View ArticleGoogle Scholar
- Liu L, Wan X, Sun L, Yang S, Dai Z, Tian Q, Lei M, Xiao X, Jiang C, Wu W (2015) RSC Adv 5:9783–9791View ArticleGoogle Scholar
- Jang S, Seo Y, Choi J, Kim T, Cho J, Kim S, Kim D (2010) Scripta Mater 62:258–261.View ArticleGoogle Scholar
- Jang S, Seo Y, Choi J, Kim T, Cho J, Kim S, Kim D (2010) Scr Mater 62:258–261View ArticleGoogle Scholar
- Lee SJ, Lee JM, Cho H-Z, Koh WG, Cheong IW, Kim JH (2010) Macromolecules 43:2484–2489View ArticleGoogle Scholar
- Wu ZH, Yang SL, Wu W (2016) Nanoscale 8:1237–1259View ArticleGoogle Scholar
- Mistry H, Reske R, Zeng Z, Zhao Z-J, Greeley J, Strasser P, Cuenya BR (2014) J Am Chem Soc 136:16473–16476View ArticleGoogle Scholar
- Juvé V, Cardinal MF, Lombardi A, Crut A, Maioli P, Pérez-Juste J, Liz-Marzán LM, Del Fatti N, Vallée F (2013) Nano Lett 13:2234–2240View ArticleGoogle Scholar
- Thouti E, Chander N, Dutta V, Komarala VK (2013) J Optics 15:035005View ArticleGoogle Scholar
- Perelaer J, Schubert US (2013) J Mater Res 28:564–573View ArticleGoogle Scholar
- Perelaer J, Smith PJ, Mager D, Soltman D, Volkman SK, Subramanian V, Korvink JG, Schubert US (2010) J Mater Chem 20:8446–8453View ArticleGoogle Scholar
- Park K, Seo D, Lee J (2008) Colloids Surf A 313:351–354View ArticleGoogle Scholar
- Layani M, Grouchko M, Shemesh S, Magdassi S (2012) J Mater Chem 22:14349–14352View ArticleGoogle Scholar
- Zhang Z, Zhu W (2015) J Alloys Compound 649:687View ArticleGoogle Scholar
- Bhat KS, Ahmad R, Wang YS, Hahn Y (2016) J Mater Chem C. doi:10.1039/C6TC02751B
- Yin W, Lee D-H, Choi J, Park C, Cho SM (2008) Korean J Chem Eng 25:1358–1361View ArticleGoogle Scholar
- TekaiaáElhsissen K (1996) J Mater Chem 6:573–577View ArticleGoogle Scholar
- Xiong Y, McLellan JM, Chen J, Yin Y, Li Z-Y, Xia Y (2005) J Am Chem Soc 127:17118–17127View ArticleGoogle Scholar
- Xiong Y, Chen J, Wiley B, Xia Y, Yin Y, Li Z-Y (2005) Nano Lett 5:1237–1242View ArticleGoogle Scholar
- Li L, Sun J, Li X, Zhang Y, Wang Z, Wang C, Dai J, Wang Q (2012) Biomaterials 33:1714–1721View ArticleGoogle Scholar
- Zhang Z, Xu F, Yang W, Guo M, Wang X, Zhang B, Tang J (2011) Chem Commun 47:6440–6442View ArticleGoogle Scholar
- Fuku K, Hayashi R, Takakura S, Kamegawa T, Mori K, Yamashita H (2013) Angew Chem Int Ed 52:7446–7450View ArticleGoogle Scholar
- Li W, Guo Y, Zhang P, Phys J (2010) Chem C 114:6413–6417Google Scholar
- Martinez-Castanon G, Nino-Martinez N, Martinez-Gutierrez F, Martinez-Mendoza J, Ruiz F (2008) J Nanopart Res 10:1343–1348View ArticleGoogle Scholar
- Christy AJ, Umadevi M (2012) Adv Nat Sci: Nanosci Nanotechnol 3:035013Google Scholar
- Kamyshny A, Magdassi S (2014) Small 10:3515–3535View ArticleGoogle Scholar
- Bakhishev T, Subramanian V (2009) J Electron Mater 38:2720–2725View ArticleGoogle Scholar
- Lakafosis V, Rida A, Vyas R, Yang L, Nikolaou S, Tentzeris MM (2010) Proc IEEE 98:1601–1609View ArticleGoogle Scholar