Yafeng Xu

Colloidal CuInS2 Quantum Dots as Inorganic Hole-Transporting Material in Perovskite Solar Cells

To develop novel hole-transporting materials (HTMs) is an important issue of perovskite solar cells (PSCs), especially favoring the stability improvement and the cost reduction. Herein, we use ternary quantum dots (QDs) as HTM in mesoporous TiO2/CH3NH3PbI3/HTM/Au solar cell, and modify the surface of CuInS2 QDs by cation exchange to improve the carrier transport. The device efficiency using CuInS2 QDs with a ZnS shell layer as HTM is 8.38% under AM 1.5, 100 mW cm(-2). The electrochemical impedance spectroscopy suggested that the significantly enhanced performance is mainly attributed to the reduced charge recombination between TiO2 and HTM. It paves a new pathway for the future development of cheap inorganic HTMs for the high efficiency PSCs.

Temperature-assisted rapid nucleation: a facile method to optimize the film morphology for perovskite solar cells

The nucleation stage has an important influence on the lead halide perovskite film morphology, and therefore the solar cell performance. Here, we introduce a facile temperature-assisted rapid nucleation (TRN) method to improve the film crystallization process and the film morphology. By employing low temperature anti-solvents (diethyl ether, chlorobenzene and toluene), we stimulate homogeneous nuclei growth, resulting in a highly dense perovskite thin layer. The TRN method prepared (FAPbI3)0.85(MAPbBr3)0.15 devices exhibit a power conversion efficiency up to 19.2% and maintain over 85% of the original efficiency after 40 days of storage at room temperature under a relative humidity of 10–40%.

Sequential deposition method fabricating carbon-based fully-inorganic perovskite solar cells

Hybrid organic-inorganic halide perovskite material has been considered as a potential candidate for various optoelectronic applications. However, their high sensitivity to the environment hampers the actual application. Hence the technology replacing the organic part of the hybrid solar cells needs to be developed. Herein, we fabricated fullyinorganic carbon-based perovskite CsPbBr3 solar cells via a sequential deposition method with a power conversion efficiency of 2.53% and long-time stability over 20 d under ambient air conditions without any encapsulation. An evolution process from tetragonal CsPb2Br5 to CsPb2Br5-CsPbBr3 composites to quasi-cubic CsPbBr3 was found, which was investigated by scanning electron microscopy, X-ray diffraction spectra, UV-vis absorption spectra and Fourier transform infrared spectroscopy. Detailed evolution process was studied to learn more information about the formation process before 10 min. Our results are helpful to the development of inorganic perovskite solar cells and the CsPb2Br5 based optoelectronic devices.摘要有机无机杂化钙钛矿是一种有潜力的光伏材料. 然而, 对于环境的高度敏感性限制了它的实际应用. 因此我们需要发展全无机钙钛矿材料. 本文通过连续沉积法制备了效率达到2.53%的碳电极CsPbBr3太阳电池, 并且它能够在无封装的情况下稳定20天. 在制备CsPbBr3薄膜的过程中, 我们首次发现从CsPb2Br5到CsPb2Br5-CsPbBr3混合物到CsPbBr3的转变. 该研究结果对于无机钙钛矿太阳电池的发展和CsPb2Br5基光电器件具有帮助作用.

Application of facile solution-processed ternary sulfide Ag 8 SnS 6 as light absorber in thin film solar cells

Light absorber is critical to the further applications of thin film solar cells. Here, we report a facile solution-processed method with an annealing temperature below 250°C to fabricate Ag8SnS6 (ATS) light absorber for thin film solar cells. After optimization, the ATS-based thin film solar cells exhibited a reproducible power conversion efficiency (PCE) of about 0.25% and an outstanding long-term stability with 90% of the initial PCE retained after a more than 1,000 h degradation test. This research revealed the potential application of ATS as an earth-abundant, low toxic and chemically stable light absorber in thin film solar cells.摘要吸光材料是薄膜太阳电池进一步应用的重要因素. 三元硫化物Ag8SnS6 (ATS)拥有诸多优秀的光电性质. 然而, 关于ATS在吸光材料方面的应用鲜有报道. 因此, 本文通过使用一种退火温度低于250°C的温和溶液法制备ATS吸光材料并将其应用于薄膜太阳电池之中. 在优化之后, 基于ATS的薄膜太阳电池展现出了具有潜力的光伏性能以及可再现的0.25%光电转化效率. 更重要的是, 基于ATS的器件展现出了卓越的长期稳定性, 在超过1000小时的老化测试后器件仍然还有90%的初始效率. 本研究不仅揭示了含量丰富、 低毒且化学性质稳定的ATS作为吸光材料的潜力, 也为薄膜太阳电池中新型吸光材料的研究提供了全新的视角.