Computational Nano-materials Design of Self-Organized Cd(Te,S) and Cd(Te,Se)Type II Nanowire (Konbu-Phase) by Spinodal Nano-Decomposition for High-Efficiency Photovoltaic Solar-Cells

Based on multi-scale simulations combined ab initio electronic structure calculation (KKR-CPA) and Monte Carlo simulation (MCS) of the two-dimensional layer-by-layer crystal growth, we have designed the self-organized quasi-one-dimensional nano-structures (Konbu-Phase) fabricated by two-dimensional spinodal nano-decomposition for high-efficiency photovoltaic solar cells (PVSCs) in Cd(Te$_{1-x}$S$_{x}$), and Cd(Te$_{1-x}$Se$_{x}$). The Konbu-Phase enhances the nano-scale electron-hole separation in PVSCs due to their Type II band alignment. The Konbu-Phase also increases the efficiency of PVSCs by multi-exciton formation using the inverse Auger effect in the self-organized quasi-one-dimensional nanostructures. We also discuss how to fabricate Konbu-Phase starting from the uniform nano-particles made by the photo-chemical reactions. Reference: M. Oshitani, K. Sato, H. Katayama-Yoshida, Applied Physics Express 4 (2011) 022302.