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Vol. 9 No. 2 (2017)

Improving the Performance of PbS Quantum Dot Solar Cells by Optimizing ZnO Window Layer

https://doi.org/10.1007/s40820-016-0124-2
Xiaokun Yang
Wuhan National Laboratory for Optoelectronics (WNLO) and School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, People’s Republic of China
Long Hu
Wuhan National Laboratory for Optoelectronics (WNLO) and School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, People’s Republic of China
Hui Deng
Wuhan National Laboratory for Optoelectronics (WNLO) and School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, People’s Republic of China
Keke Qiao
Wuhan National Laboratory for Optoelectronics (WNLO) and School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, People’s Republic of China
Chao Hu
Wuhan National Laboratory for Optoelectronics (WNLO) and School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, People’s Republic of China
Zhiyong Liu
State Key Laboratory of Digital Manufacturing Equipment and Technology, Huazhong University of Science and Technology, Wuhan 430074, People’s Republic of China
Shengjie Yuan
Wuhan National Laboratory for Optoelectronics (WNLO) and School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, People’s Republic of China
Jahangeer Khan
Wuhan National Laboratory for Optoelectronics (WNLO) and School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, People’s Republic of China
Dengbing Li
Wuhan National Laboratory for Optoelectronics (WNLO) and School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, People’s Republic of China
Jiang Tang
Wuhan National Laboratory for Optoelectronics (WNLO) and School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, People’s Republic of China
Haisheng Song
Wuhan National Laboratory for Optoelectronics (WNLO) and School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, People’s Republic of China
Chun Cheng
Department of Materials Science and Engineering and Shenzhen Key Laboratory of Nanoimprint Technology, South University of Science and Technology, Shenzhen 518055, People’s Republic of China

Corresponding Author: Chun Cheng

chengc@sustc.edu.cn

Nano-Micro Letters, Vol. 9 No. 2 (2017), Article Number: 24

Abstract

Comparing with hot researches in absorber layer, window layer has attracted less attention in PbS quantum dot solar cells (QD SCs). Actually, the window layer plays a key role in exciton separation, charge drifting, and so on. Herein, ZnO window layer was systematically investigated for its roles in QD SCs performance. The physical mechanism of improved performance was also explored. It was found that the optimized ZnO films with appropriate thickness and doping concentration can balance the optical and electrical properties, and its energy band align well with the absorber layer for efficient charge extraction. Further characterizations demonstrated that the window layer optimization can help to reduce the surface defects, improve the heterojunction quality, as well as extend the depletion width. Compared with the control devices, the optimized devices have obtained an efficiency of 6.7% with an enhanced V oc of 18%, J sc of 21%, FF of 10%, and power conversion efficiency of 58%. The present work suggests a useful strategy to improve the device performance by optimizing the window layer besides the absorber layer.


Highlights:


1 The efficiencies of PbS solar cells was significantly improved from 4.3% to 6.7% by optimizing ZnO window layer.
2 Optimized ZnO window layer can reduce the surface defects, extend thedepleted-heterojunction width and align with energy band of absorber layer.

Keywords

ZnO Window layer Thin film solar cells PbS quantum dots Physical mechanism
Yang, Xiaokun, Long Hu, Hui Deng, Keke Qiao, Chao Hu, Zhiyong Liu, Shengjie Yuan, Jahangeer Khan, Dengbing Li, Jiang Tang, Haisheng Song, and Chun Cheng. 2017. “Improving the Performance of PbS Quantum Dot Solar Cells by Optimizing ZnO Window Layer”. Nano-Micro Letters 9 (2):24. https://doi.org/10.1007/s40820-016-0124-2.
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References
  1. O.E. Semonin, J.M. Luther, S. Choi, H.-Y. Chen, J. Gao, A.J. Nozik, M.C. Beard, Peak external photocurrent quantum efficiency exceeding 100% via MEG in a quantum dot solar cell. Science 334(6062), 1530–1533 (2011). doi:10.1126/science.1209845
  2. M. Graetzel, R.A.J. Janssen, D.B. Mitzi, E.H. Sargent, Materials interface engineering for solution-processed photovoltaics. Nature 488(7411), 304–312 (2012). doi:10.1038/nature11476
  3. C.H.M. Chuang, P.R. Brown, V. Bulovic, M.G. Bawendi, Improved performance and stability in quantum dot solar cells through band alignment engineering. Nat. Mater. 13(8), 796–801 (2014). doi:10.1038/nmat3984
  4. S.A. McDonald, G. Konstantatos, S. Zhang, P.W. Cyr, E.J.D. Klem, L. Levina, E.H. Sargent, Solution-processed PbS quantum dot infrared photodetectors and photovoltaics. Nat. Mater. 4(2), 138–142 (2005). doi:10.1038/nmat1299
  5. G. Konstantatos, E.H. Sargent, PbS colloidal quantum dot photoconductive photodetectors: transport, traps, and gain. Appl. Phys. Lett. 91(17), 173505 (2007). doi:10.1063/1.2800805
  6. K. Qiao, H. Deng, X. Yang, D. Dong, M. Li, L. Hu, H. Liu, H. Song, J. Tang, Spectra-selective PbS quantum dot infrared photodetectors. Nanoscale 8(13), 7137–7143 (2016). doi:10.1039/C5NR09069E
  7. G. Konstantatos, C. Huang, L. Levina, Z. Lu, E.H. Sargent, Efficient infrared electroluminescent devices using solution-processed colloidal quantum dots. Adv. Funct. Mater. 15(11), 1865–1869 (2005). doi:10.1002/adfm.200500379
  8. L. Sun, J.J. Choi, D. Stachnik, A.C. Bartnik, B.-R. Hyun, G.G. Malliaras, T. Hanrath, F.W. Wise, Bright infrared quantum-dot light-emitting diodes through inter-dot spacing control. Nat. Nanotechnol. 7(6), 369–373 (2012). doi:10.1038/nnano.2012.63
  9. H. Lee, H.C. Leventis, S.-J. Moon, P. Chen, S. Ito et al., PbS and CdS quantum dot-sensitized solid-state solar cells: “old concepts, new results”. Adv. Funct. Mater. 19(17), 2735–2742 (2009). doi:10.1002/adfm.200900081
  10. G.I. Koleilat, L. Levina, H. Shukla, S.H. Myrskog, S. Hinds, A.G. Pattantyus-Abraham, E.H. Sargent, Efficient, stable infrared photovoltaics based on solution-cast colloidal quantum dots. ACS Nano 2(5), 833–840 (2008). doi:10.1021/nn800093v
  11. J. Tang, L. Brzozowski, D.A.R. Barkhouse, X. Wang, R. Debnath et al., Quantum dot photovoltaics in the extreme quantum confinement regime: the surface-chemical origins of exceptional air- and light-stability. ACS Nano 4(2), 869–878 (2010). doi:10.1021/nn901564q
  12. X. Lan, O. Voznyy, A. Kiani, F.P. Garcia de Arquer, A.S. Abbas et al., Passivation using molecular halides increases quantum dot solar cell performance. Adv. Mater. 28(2), 299–304 (2016). doi:10.1002/adma.201503657
  13. M. Liu, F.P. de Arquer, Y. Li, X. Lan, G.H. Kim et al., Double-sided junctions enable high-performance colloidal-quantum-dot photovoltaics. Adv. Mater. 28(21), 4142–4148 (2016). doi:10.1002/adma.201506213
  14. C.H. Chuang, P.R. Brown, V. Bulovic, M.G. Bawendi, Improved performance and stability in quantum dot solar cells through band alignment engineering. Nat. Mater. 13(8), 796–801 (2014). doi:10.1038/nmat3984
  15. J. Luo, X. Dai, S. Bai, Y. Jin, Z. Ye, X. Guo, Ligand exchange of colloidal ZnO nanocrystals from the high temperature and nonaqueous approach. Nano-Micro Lett. 5(4), 274–280 (2013). doi:10.1007/BF03353758
  16. G.H. Kim, F.P. Garcia de Arquer, Y.J. Yoon, X. Lan, M. Liu et al., High-efficiency colloidal quantum dot photovoltaics via robust self-assembled monolayers. Nano Lett. 15(11), 7691–7696 (2015). doi:10.1021/acs.nanolett.5b03677
  17. Z. Yang, A. Janmohamed, X. Lan, F.P. Garcia de Arquer, O. Voznyy et al., Colloidal quantum dot photovoltaics enhanced by perovskite shelling. Nano Lett. 15(11), 7539–7543 (2015). doi:10.1021/acs.nanolett.5b03271
  18. S. Bai, Z. Wu, X. Xu, Y. Jin, B. Sun et al., Inverted organic solar cells based on aqueous processed ZnO interlayers at low temperature. Appl. Phys. Lett. 100(20), 203906 (2012). doi:10.1063/1.4719201
  19. L.K. Jagadamma, M. Abdelsamie, A. El Labban, E. Aresu, G.O. Ngongang Ndjawa, D.H. Anjum, D. Cha, P.M. Beaujuge, A. Amassian, Efficient inverted bulk-heterojunction solar cells from low-temperature processing of amorphous ZnO buffer layers. J. Mater. Chem. A 2(33), 13321–13331 (2014). doi:10.1039/C4TA02276A
  20. J. You, C.-C. Chen, L. Dou, S. Murase, H.-S. Duan et al., Metal oxide nanoparticles as an electron-transport layer in high-performance and stable inverted polymer solar cells. Adv. Mater. 24(38), 5267–5272 (2012). doi:10.1002/adma.201201958
  21. E.A. Manor, T. Katz, F.C. Tromholt, Krebs, Enhancing functionality of ZnO hole blocking layer in organic photovoltaics. Sol. Energy Mater. Sol. Cells 98, 491–493 (2012). doi:10.1016/j.solmat.2011.11.026
  22. C.E. Small, S. Chen, J. Subbiah, C.M. Amb, S.-W. Tsang, T.-H. Lai, J.R. Reynolds, F. So, High-efficiency inverted dithienogermole-thienopyrrolodione- based polymer solar cells. Nat. Photon. 6(2), 115–120 (2012). doi:10.1038/nphoton.2011.317
  23. L. Guo, S. Yang, C. Yang, P. Yu, J. Wang, W. Ge, G.K.L. Wong, Highly monodisperse polymer-capped ZnO nanoparticles: preparation and optical properties. Appl. Phys. Lett. 76(20), 2901–2903 (2000). doi:10.1063/1.126511
  24. H. Zhang, R.C. Shallcross, N. Li, T. Stubhan, Y. Hou, W. Chen, T. Ameri, M. Turbiez, N.R. Armstrong, C.J. Brabec, Overcoming electrode-induced losses in organic solar cells by tailoring a quasi-ohmic contact to fullerenes via solution-processed alkali hydroxide layers. Adv. Energy Mater. 6(9), 1502195 (2016). doi:10.1002/aenm.201502195
  25. B.R. Lee, E.D. Jung, Y.S. Nam, M. Jung, J.S. Park et al., Amine-based polar solvent treatment for highly efficient inverted polymer solar cells. Adv. Mater. 26(3), 494–500 (2014). doi:10.1002/adma.201302991
  26. R. Azmi, H. Aqoma, W.T. Hadmojo, J.-M. Yun, S. Yoon, K. Kim, Y.R. Do, S.-H. Oh, S.-Y. Jang, Low-temperature-processed 9% colloidal quantum dot photovoltaic devices through interfacial management of p-n heterojunction. Adv. Energy Mater. 6(8), 1502146 (2016). doi:10.1002/aenm.201502146
  27. S. Nho, G. Baek, S. Park, B.R. Lee, M.J. Cha et al., Highly efficient inverted bulk-heterojunction solar cells with a gradiently-doped ZnO layer. Energy Environ. Sci. 9(1), 240–246 (2016). doi:10.1039/C5EE03045E
  28. S. Kwon, K.-G. Lim, M. Shim, H.C. Moon, J. Park et al., Air-stable inverted structure of hybrid solar cells using a cesium-doped ZnO electron transport layer prepared by a sol–gel process. J. Mater. Chem. A 1(38), 11802–11808 (2013). doi:10.1039/c3ta12425h
  29. B.S. Ong, C. Li, Y. Li, Y. Wu, R. Loutfy, Stable, solution-processed, high-mobility ZnO thin-film transistors. J. Am. Chem. Soc. 129(10), 2750–2751 (2007). doi:10.1021/ja068876e
  30. B. Du Ahn, S.H. Oh, C.H. Lee, G.H. Kim, H.J. Kim, S.Y. Lee, Influence of thermal annealing ambient on Ga-doped ZnO thin films. J. Cryst. Growth 309(2), 128–133 (2007). doi:10.1016/j.jcrysgro.2007.09.014
  31. L. Hu, D.-B. Li, L. Gao, H. Tan, C. Chen et al., Graphene doping improved device performance of ZnMgO/PbS colloidal quantum dot photovoltaics. Adv. Funct. Mater. 26(12), 1899–1907 (2016). doi:10.1002/adfm.201505043
  32. Y.S. Wang, P.J. Thomas, P. O’Brien, Optical properties of ZnO nanocrystals doped with Cd, Mg, Mn, and Fe Ions. J. Phys. Chem. B 110(43), 21412–21415 (2006). doi:10.1021/jp0654415
  33. H. Zeng, W. Cai, J. Hu, G. Duan, P. Liu, Y. Li, Violet photoluminescence from shell layer of Zn/ZnO core-shell nanoparticles induced by laser ablation. Appl. Phys. Lett. 88(17), 171910 (2006). doi:10.1063/1.2196051
  34. P.K. Nayak, J. Bisquert, D. Cahen, Assessing possibilities and limits for solar cells. Adv. Mater. 23(25), 2870–2876 (2011). doi:10.1002/adma.201100877
  35. R.C. Rai, Analysis of the Urbach tails in absorption spectra of undoped ZnO thin films. J. Appl. Phys. 113(15), 153508 (2013). doi:10.1063/1.4801900
  36. G.T. Ramesh, R. Gopikrishnan, K. Zhang, P. Ravichandran, S. Baluchamy et al., Synthesis, characterization and biocompatibility studies of zinc oxide (ZnO) nanorods for biomedical application. Nano-Micro Lett. 2(1), 31–36 (2010). doi:10.1007/BF03353614
  37. Y. Sun, J.H. Seo, C.J. Takacs, J. Seifter, A.J. Heeger, Inverted polymer solar cells integrated with a low-temperature-annealed sol-gel-derived ZnO Film as an electron transport layer. Adv. Mater. 23(14), 1679–1683 (2011). doi:10.1002/adma.201004301
  38. D. Yang, B. Li, C. Hu, H. Deng, D. Dong, X. Yang, K. Qiao, S. Yuan, H. Song, Controllable growth orientation of SnS2 flakes for low-noise, high-photoswitching ratio, and ultrafast phototransistors. Adv. Opt. Mater. 4(3), 419–426 (2016). doi:10.1002/adom.201500506
  39. S. Christoulakis, M. Suchea, E. Koudoumas, M. Katharakis, N. Katsarakis, G. Kiriakidis, Thickness influence on surface morphology and ozone sensing properties of nanostructured ZnO transparent thin films grown by PLD. Appl. Surf. Sci. 252(15), 5351–5354 (2006). doi:10.1016/j.apsusc.2005.12.071
  40. J.R. Sites, P.H. Mauk, Diode quality factor determination for thin-film solar cells. Solar Cells 27(1), 411–417 (1989). doi:10.1016/0379-6787(89)90050-1
  41. V. Nadenau, U. Rau, A. Jasenek, H. Schock, Electronic properties of CuGaSe2-based heterojunction solar cells. Part I. Transport analysis. J. Appl. Phys. 87(1), 584–593 (2000). doi:10.1063/1.371903
  42. P. Schilinsky, C. Waldauf, J. Hauch, C.J. Brabec, Simulation of light intensity dependent current characteristics of polymer solar cells. J. Appl. Phys. 95(5), 2816–2819 (2004). doi:10.1063/1.1646435
  43. P.R. Brown, R.R. Lunt, N. Zhao, T.P. Osedach, D.D. Wanger, L.-Y. Chang, M.G. Bawendi, V. Bulovic, Improved current extraction from ZnO/PbS quantum dot heterojunction photovoltaics using a MoO3 interfacial layer. Nano Lett. 11(7), 2955–2961 (2011). doi:10.1021/nl201472u
  44. S.M. Willis, C. Cheng, H.E. Assender, A.A. Watt, The transitional heterojunction behavior of PbS/ZnO colloidal quantum dot solar cells. Nano Lett. 12(3), 1522–1526 (2012). doi:10.1021/nl204323j
  45. L.H. Quang, S.J. Chua, K. Ping Loh, E. Fitzgerald, The effect of post-annealing treatment on photoluminescence of ZnO nanorods prepared by hydrothermal synthesis. J. Cryst. Growth 287(1), 157–161 (2006). doi:10.1016/j.jcrysgro.2005.10.060
  46. Y.G. Wang, S.P. Lau, H.W. Lee, S.F. Yu, B.K. Tay, X.H. Zhang, H.H. Hng, Photoluminescence study of ZnO films prepared by thermal oxidation of Zn metallic films in air. J. Appl. Phys. 94(1), 354–358 (2003). doi:10.1063/1.1577819
  47. L.Y. Chang, R.R. Lunt, P.R. Brown, V. Bulovic, M.G. Bawendi, Low-temperature solution-processed solar cells based on PbS colloidal quantum dot/CdS heterojunctions. Nano Lett. 13(3), 994–999 (2013). doi:10.1021/nl3041417
  48. H. Lawrence, R.M. Warner, Diffused junction depletion layer calculations. Bell Syst. Tech. J. 39(2), 389–430 (1960). doi:10.1002/j.1538-7305.1960.tb01607.x
  49. T. Prasada Rao, G.K. Goswami, K.K. Nanda, Detailed understanding of the excitation-intensity dependent photoluminescence of ZnO materials: role of defects. J. Appl. Phys. 115(21), 213513 (2014). doi:10.1063/1.4881779
  50. S. Chen, C.E. Small, C.M. Amb, J. Subbiah, T.H. Lai, S.W. Tsang, J.R. Manders, J.R. Reynolds, F. So, Inverted polymer solar cells with reduced interface recombination. Adv. Energy Mater. 2(11), 1333–1337 (2012). doi:10.1002/aenm.201200184
  51. H. Zeng, G. Duan, Y. Li, S. Yang, X. Xu, W. Cai, Blue luminescence of ZnO nanoparticles based on non-equilibrium processes: defect origins and emission controls. Adv. Funct. Mater. 20(4), 561–572 (2010). doi:10.1002/adfm.200901884
  52. T.P. Osedach, N. Zhao, S.M. Geyer, L.Y. Chang, D.D. Wanger, A.C. Arango, M.C. Bawendi, V. Bulovic, Interfacial recombination for fast operation of a planar organic/QD infrared photodetector. Adv. Mater. 22(46), 5250–5254 (2010). doi:10.1002/adma.201002589
  53. J.R. Sizelove, Residual native shallow donor in ZnO. Phys. Rev. Lett. 82(12), 2552–2555 (1998). doi:10.1103/PhysRevLett.82.2552
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