Proposal of simplified model for absorption coefficients in quantum dot array based intermediate band solar cell structure

Abstract

We propose a simplified theoretical model to analyze the absorption coefficients in quantum dot intermediate band solar cell (QD-IBSC) structure. Our theoretical model, based on the multiband tight-binding Hamiltonian including the conduction, valence, and the intermediate band, can capture some essential features in the actual QD-IBSC such as the absorption path dependence of the absorption strength and the line shape of the absorption spectrum in spite of its simplicity. The main feature of this model is its ability to be applied to any QD-IBSC system regardless of the geometrical parameters (QDs shapes and spacing) or the base materials by changing the relevant coupling parameters. The proposed simplified should be of useful for the semi-quantitative understanding and modeling of QD-IBSC.

Two-step photon up-conversion solar cells

“…According to ideal theoretical predictions, the IBSC is expected to exhibit extremely high conversion efficiency, >60%, under the maximum concentration and 48.2% under one-sun irradiation5. Substantial progress has been made in this field101112131415161718192021222324252627 since Luque and Martí have proposed this concept of IBSC in 1997 (ref. 5).…”