Proceedings of International Conference on Perovskite and Organic Photovoltaics and Optoelectronics (IPEROP19)
Publication date: 23rd October 2018
Organic-inorganic perovskite compounds exhibit interesting properties, such as high photoelectric conversion efficiency, and have been widely studied. The structural stability of B site substituted perovskite compounds was examined by first-principles calculations and the cluster expansion method[1]. At T = 0, the inorganic systems Cs(Pb,Sn)I3, Cs(Pb,Ge)I3, and Cs(Ge,Sn)I3 are stable, while the introduction of formamidinium and methylammonium destabilize the systems. In this study, the transport properties of the stable compounds in the B site substituted systems were examined by BoltzTraP calculation[2].
From a ground state search by cluster expansion, the Cs(Pb,Sn)I3 system was demonstrated to adopt two stable structures, CsPb0.875Sn0.125I3 and CsPb0.125Sn0.875I3. The carrier concentration dependence of the Seebeck coefficients increased in the p-type region as the Pb content increased. On the other hand, electric and thermal conductivities increase with increasing Sn content. These transport properties increased with increasing at 300 K < T < 700 K. The relationship between the electronic state of the partial substituted structures and transport properties are discussed in detail herein.