中国物理B ›› 2016, Vol. 25 ›› Issue (2): 27104-027104.doi: 10.1088/1674-1056/25/2/027104
• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇 下一篇
Qing-Yuan Chen(陈清源), Yang Huang(黄杨), Peng-Ru Huang(黄鹏儒) Tai Ma(马泰), Chao Cao(曹超), Yao He(何垚)
Qing-Yuan Chen(陈清源)1, Yang Huang(黄杨)1, Peng-Ru Huang(黄鹏儒)1 Tai Ma(马泰)1, Chao Cao(曹超)2, Yao He(何垚)1
摘要: Organic-inorganic hybrid perovskites play an important role in improving the efficiency of solid-state dye-sensitized solar cells. In this paper, we systematically explore the efficiency-enhancing mechanism of ABX3 (A =CH3NH3; B = Sn, Pb; X = Cl, Br, I) and provide the best absorber among ABX3 when the organic framework A is CH3NH3 by first-principles calculations. The results reveal that the valence band maximum (VBM) of the ABX3 is mainly composed of anion X p states and that conduction band minimum (CBM) of the ABX3 is primarily composed of cation B p states. The bandgap of the ABX3 decreases and the absorptive capacities of different wavelengths of light expand when reducing the size of the organic framework A, changing the B atom from Pb to Sn, and changing the X atom from Cl to Br to I. Finally, based on our calculations, it is discovered that CH3NH3SnI3 has the best optical properties and its light-adsorption range is the widest among all the ABX3 compounds when A is CH3NH3. All these results indicate that the electronegativity difference between X and B plays a fundamental role in changing the energy gap and optical properties among ABX3 compounds when A remains the same and that CH3NH3SnI3 is a promising perovskite absorber in the high efficiency solar batteries among all the CH3NH3BX3 compounds.
中图分类号: (Polymers and organic compounds)