Modeling of energy bands in ultra-thin layer quantum nanostructures for solar cell applications

In this paper we propose a simple calculation of the energy band in nano-structured meta-materials based on ultra-thin periodic Si/SiO₂ layers (quantum-well superlattice) for third-generation solar cell application. For this purpose, the Schrödinger equation (with periodic Bloch's conditions) is numerically solved considering the exact potential profiles of both the valence and conduction bands of the Si/SiO₂ system. This method allows us to analyze the carrier energy band structure and to extract the essential electronic properties (bandgaps, miniband widths) of such 1-D periodic nanostructures. The energy band structure and more particularly the meta-material bandgap is found to strongly depend on quantum well thickness and spacing.