ELECTRONIC STRUCTURE, TRANSPORT, AND OPTICAL PROPERTIES OF CSPBX3 (X = CL, BR, I) COMPOUNDS

• Main Author: Taffarel, Hansel
• Format: Final Project
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/64819
• Institution: Institut Teknologi Bandung

Global warming causes more and more parties to realize the need to reduce the energy dependence on the fossil-based resources. Solar cell is one of the electrical energy producing devices with a lot of advantages such as envirommentally friendly and unlimited resources. Solar cells have significantly developed, with Dye-Sensitized Solar Cell (DSSC) is the latest generation of solar cell. DSSC can use CH3NH3PbI3 as materials to absorb lights (dyes) with high energy conversion. However, this material has many disadvantages, one of them is that this material is unstable at high temperature and under UV lights. Therefore, it is necessary to develop alternative materials that have the same advantages as CH3NH3PbI3, namely CsPbX3 (X = Cl, Br, I). Computational studies have been carried out on CsPbX3 (X = Cl, Br, I), but no one has reported the relativistic effect as spin-orbit coupling in computational calculations. On the other side, to study complex materials, it needs a faster and accurate calculations. One of the methods to speed up the calculations is by using Graphical Processing Unit (GPU). In this research, computational calculations have been carried out to determine physical properties of CsPbX3 (X = Cl, Br, I) such as band structures, transport properties, and optical properties. Band gap width (Eg) for CsPbX3 (X = Cl, Br, I) decrease as spin-orbit coupling present, with Eg CsPbCl3 non-SOC = 1.8114 eV; Eg CsPbCl3 SOC = 0.6827 eV; Eg CsPbBr3 non-SOC = 2.0934 eV; Eg CsPbBr3 SOC = 0.9807 eV; Eg CsPbI3 non-SOC = 2.4741 eV; and Eg CsPbI3 SOC = 1.9211 eV. For transport properties, at 600 K and ? = 0.5 eV, electrical conductivity of CsPbCl3, CsPbBr3, and CsPbI3 are 1.25×1018 (?.m.s)-1, 1.25×1012 (?.m.s)-1, and 1.51×1017 (?.m.s)-1, respectively. Optical properties shows that all the first absorption peak of CsPbCl3 and CsPbBr3 are close to the band gap energy values for each material. Calculation using CPU and GPU shows that there is no difference in calculations in terms of accuracy and calculation with GPU is 2 times faster than using CPU only.