Li Dehui, Cheng Hung-Chieh, Wu Hao, Wang Yiliu, Guo Jian, Wang Gongming, Huang Yu, Duan Xiangfeng
Department of Chemistry and Biochemistry, University of California , Los Angeles, California 90095, United States.
School of Optical and Electronic Information, Huazhong University of Science and Technology , Wuhan 430074, China.
J Phys Chem Lett. 2017 Jan 19;8(2):429-434. doi: 10.1021/acs.jpclett.6b02841. Epub 2017 Jan 5.
Understanding the intrinsic charge transport in organolead halide perovskites is essential for the development of high-efficiency photovoltaics and other optoelectronic devices. Despite the rapid advancement of the organolead halide perovskite in photovoltaic and optoelectronic applications, the intrinsic charge-carrier transport in these materials remains elusive partly due to the difficulty of fabricating electrical devices and obtaining good electrical contact. Here we report the fabrication of organolead halide perovskite microplates with mono- or bilayer graphene as low barrier electrical contact. Systematic charge-transport studies reveal an insulator to band-like transport transition. Our studies indicate that the insulator to band-like transport transition depends on the orthorhombic-to-tetragonal phase-transition temperature and defect densities of the organolead halide perovskite microplates. Our findings not only are important for the fundamental understanding of charge-transport behavior but also offer valuable practical implications for photovoltaics and optoelectronic applications based on the organolead halide perovskite.
了解有机铅卤化物钙钛矿中的本征电荷传输对于高效光伏和其他光电器件的发展至关重要。尽管有机铅卤化物钙钛矿在光伏和光电器件应用方面取得了快速进展，但这些材料中的本征电荷载流子传输仍然难以捉摸，部分原因是制造电气设备和获得良好电接触存在困难。在此，我们报告了以单层或双层石墨烯作为低势垒电接触的有机铅卤化物钙钛矿微板的制备。系统的电荷传输研究揭示了从绝缘体到带状传输的转变。我们的研究表明，从绝缘体到带状传输的转变取决于有机铅卤化物钙钛矿微板的正交晶系到四方晶系的相变温度和缺陷密度。我们的发现不仅对于电荷传输行为的基本理解很重要，而且对于基于有机铅卤化物钙钛矿的光伏和光电器件应用也具有宝贵的实际意义。
