First Principle Study On The Electronic Properties And Optical Properties Of Perovskite Materials

Since the 21st century, along with the environmental and energy problem increasingly serious, in order to realize the sustainable development of human society, environmental pollution and the development of new energy is an important research direction of the scientific workers. The study on the degradation of organic pollutants by hydrogen production is attracted more and more people pain attention to search such kind of photocatalyst, which absorbs wide range sunlight and has high photocatalytic efficiency. Solar energy is the sustainable development of the earth's most abundant energy, so it is bound to ease or even completely solve the problem of energy if we can effectively utilize solar energy. Although traditional silicon-based solar cells has realized industrialization, the problems of pollution and energy consumption are more serious. Therefore, research and development of novel solar cells is necessary. In this paper, we calculated and studied the BiVO3 and CH3NH3SnI3 by using the first principle theory, respectively.Firstly, The structural, electronic, magnetic and optical properties of bulk BiVO3 were investigated by first-principle calculations. The calculated results show that the ground state of BiV03 perovskites is Pnma with C-type antiferromagnetic ordering (C-AFM) with the band gap about 1.79 eV. The hybridization between Bi-0 and V-0 with interplay play important roles for the nature of the ferromagnetism and the magnetic ordering temperature is estimated to be?21 K. Furthermore, our study shows that it has strong light absorption, but low reflection efficiency between 400 nm and 760 nm in the visible light region. It indicates that BiVO3 will be a promising photocatalyst with favorable photocatalytic activity in the visible region. Our results will provide theoretical guidance for BiVO3 synthesis and application.Secondly, We calculated the electronic properties and carrier mobility of perovskite CH3NH3SnI3 as a solar cell absorber by using hybrid functional method. The calculated result shows that the electron and hole mobilities are anisotropy with the large magnitude of 1.4×104 cm2V-1s-1 along y direction. In view of huge difference between hole and electron mobilities, the perovskite CH3NH3SnI3 can be considered as a p-type semiconductor. We also discovered there is an anisotropy relationship of the effective masses and electronic occupation. The above results can provide reliable guidance for its experimental applications to electronics and optoelectronics.