基于石墨烯/CuInS2的杂化聚合物太阳电池性能研究

摘要/Abstract

摘要： 用石墨烯/CuInS2量子点复合物（rGO/CuInS2-QDs）和聚（2-甲氧基-5-(2-乙基己氧基)-1,4-对苯乙炔）（MEH-PPV）制备了MEH-PPV/rGO-CuInS2杂化聚合物太阳电池。用动态测试的方法研究了电池的电荷传输动力学特点。实验结果表明，与MEH-PPV/rGO器件相比，MEH-PPV/rGO-CuInS2器件的电子传输时间和电子寿命均有显著的增加，我们认为两者增加的主要原因分别是由于CuInS2量子点的表面缺陷态捕获和CuInS2量子点作为阻挡层的存在促进了电子-空穴对的有效分离。而且，我们证实了MEH-PPV/rGO-CuInS2电池中短路电流的增加主要与聚合物中激子分离增加和载流子复合减少有关；器件的开路电压主要是由石墨烯的功函和聚合物的最高已占分子轨道（HOMO）之间的能级差决定，同时受石墨烯中电子浓度的影响。

关键词: CuInS2

Abstract: Solar cells are fabricated by blending the reduced graphene oxide-CuInS2 quantum dots hybrid (rGO/CuInS2-QDS) with poly(2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene vinylene) (MEH-PPV), producing MEH-PPV/rGO-CuInS2 devices. We studied the MEH-PPV/rGO-CuInS2 devices with dynamic method to reveal the features in charge transport dynamics in the devices. The results show that the MEH-PPV/rGO-CuInS2 devices exhibit significantly increased electron transit time and electron lifetime, which are attributed to the surface electron trapping on the CuInS2-QDS and the barrier effect of CuInS2-QDS on the rGO sheets by increasing the spatial e?h separation, respectively. Moreover, it is demonstrated that the increased short-circuit current in the MEH-PPV/rGO-CuInS2 devices is mainly related to the increased polymer exciton dissociation and reduced charge recombination, while the open-circuit voltage is determined by the energy difference between the highest occupied molecular orbital level of MEH-PPV and the work-function of rGO but significantly correlates with the concentration of the electrons in rGO.

Key words: CuInS2

孟维利董超齐娟娟陈俊伟. 基于石墨烯/CuInS2的杂化聚合物太阳电池性能研究[J]. J4, 2018, 35(1): 86-94.

参考文献

[1] Günes S, Neugebauer H, Sariciftci N S. Conjugated polymer-based organic solar cells [J]. Chem Rev, 2007, 107:1324?1338.
[2] Yip H L, Jen K Y. Recent advances in solution-processed interfacial materials for efficient and stable polymer solar cells [J]. Energy Environ Sci, 2012, 5:5994?6011.
[3] Rao C N R, Sood A K, Subrahmanyam K S, Govindaraj A. Graphene: the new two-dimensional nanomaterial [J]. Angew Chem Int Ed, 2009, 48:7752?7777.
[4] Tang L, Wang Y, Li Y, Feng H, Lu J, Li J. Preparation, structure and electrochemical properties of graphene modified electrode [J]. Adv Funct Mater, 2009, 19:2782?2789.
[5] Bonaccorso F, Sun Z, Hasan T, Ferrari A C. Graphene photonics and optoelectronics [J]. Nat Photonics, 2010, 4:611?622.
[6] Bae S, Kim H, Lee Y, Xu X F, Park J -S, Zheng Y, et al. Roll-to-roll production of 30-inch graphene films for transparent electrodes [J]. Nat Nanotechnol, 2010, 5:574?578.
[7] Wang X, Zhi L J, Mullen K. Transparent, conductive graphene electrodes for dye-sensitized solar cells [J]. Nano Lett, 2008, 8:323?327.
[8] Yin Z Y, Sun S Y, Salim T, Wu S X, Huang X A, He Q Y, et al, Organic photovoltaic devices using highly flexible reduced graphene oxide films as transparent electrode [J]. ACS Nano, 2010, 4:5263–5268.
[9] Lee Y -Y, Tu K -H, Yu C -C, Li S -S, Hwang J -Y, Lin C -C, et al. Top laminated graphene electrode in a semitransparent polymer solar cell by simultaneous thermal annealing/releasing method [J]. ACS Nano, 2011, 5:6564?6570.
[10] Liu Z F, Liu Q, Huang Y, Ma Y F, Yin S G, Zhang X Y, et al. Organic photovoltaic devices based on a novel acepptor material: graphene [J]. Adv Mater, 2008, 20:3924–3930.
[11] Wang H T, He D W, Wang Y S, Liu Z Y, Wu H P, Wang J G. Organic photovoltaic devices based on graphene as an electron-acceptor material and P3OT as a donor material [J]. Phys Status Solidi A, 2011, 208:2339?2343.
[12] Guo C, Yang H, Sheng Z, Lu Z, Song Q, Li C. Layered graphene/quantum dots for photovoltaic devices [J]. Angew Chem Int Ed, 2010, 49:3014–3017.
[13] Yun J -M, Yeo J -S, Kim J, Jeong H -G, Kim D -Y, Noh Y -J. et al. Solution-processable reduced graphene oxide as a novel alternative to PEDOT: PSS hole transport layers for highly efficient and stable polymer solar cells [J]. Adv Mater, 2011, 23:4923?4928.
[14] Liu X, Kim H, Guo L. Optimization of thermally reduced graphene oxide for an efficient hole transport layer in polymer solar cells [J]. Organic Electronics, 2013, 14:591–598.
[15] Lewerenz H J. Development of copper indium disulfide into a solar material [J]. Sol Energ Mat Sol C, 2004, 83:395–407.
[16] Klenk R, Klaer J, Scheer R, Lux-Steiner MC, Luck I, Meyer N, et al. Solar cells based on CuInS2?an overview [J]. Thin Solid Films, 2005, 480–481:509–514.
[17] Meng W, Zhou X, Qiu Z, Liu C, Chen J, Yue W, et al. Reduced graphene oxide-supported aggregates of CuInS2 quantum dots as an effective hybrid electron acceptor for polymer-based solar cells [J]. Carbon, 2016, 96:53–540.
[18] Binsma J J M, Giling L J, Bloem J. Luminescence of CuInS2: ?. The broad band emission and its dependence on the defect chemistry [J]. J Lumin, 1982, 27:35–53.
[19] Ueng H Y, Hwang H L. The defect structure of CuInS2. part ? intrinsic defects [J]. J Phys Chem Solid, 1989, 50:1297–1305.
[20] Yoshino K, Nomoto K, Kinoshita A, Ikari T, Akaki Y, Yoshitake T. Dependence of Cu/In ratio of structural and electrical characterization of CuInS2 crystal [J]. J Mater Sci: Mater Electron, 2008, 19:301–304.
[21] Liu Q, Liu Z, Zhang X, Yang L, Zhang N, Pan G, et al. Polymer photovoltaic cells based on solution-processable graphene and P3HT [J]. Adv Funct Mater, 2009, 19:894–904.
[22] Dloczik L, Ileperuma O, Lauermann I, Peter L M, Ponomarev E A, Redmond G, Shaw N J, Uhlendorf I. Dynamic response of dye-sensitized nanocrystalline solar cells: characterization by intensity-modulated photocurrent spectroscopy [J]. J Phys Chem B, 1997, 101:10281–10289.
[23] Dunn H K, Peter L M. How efficient is electron collection in dye-sensitized solar cells comparison of different dynamic methods for the determination of the electron diffusion length [J]. J Phys Chem C, 2009, 113:4726–4731.
[24] Qi J J, Chen J W, Meng W L, Wu X Y, Liu C W, Yue W J, et al. Recent advances in hybrid solar cells based on metal oxide nanostructures [J]. Synth Metals, 2015, http://dx.doi.org/10.1016/j.synthmet.2016.04.027.
[25] Cui Q, Liu C W, Wu F, Yue W J, Qiu Z L, Zhang H, et al. Performance improvement in polymer/ZnO nanoarray hybrid solar cells by formation of ZnO/CdS-core/shell heterostructures [J]. J Phys Chem C, 2013, 117:5626?5637.
[26] Noone K M, Subramaniyan S, Zhang Q F, Cao G Z, Jenekhe S A, Ginger D S. Photoinduced charge transfer and polaron dynamics in polymer and hybrid photovoltaic thin films: organic vs inorganic acceptors [J]. J Phys Chem C, 2011, 115:24403–24410.
[27] Wong D K -P, Ku C -H, Chen Y -R, Chen G -R, Wu J -J. Enhancing electron collection efficiency and effective diffusion length in dye-sensitized solar cells [J]. Chem Phys Chem, 2009, 10:2698–2702.