Nanostructure design optimization for solar energy harvesting

Abstract

Solar energy is one of the most important clean energy on earth. With the utilization of solar light, solar energy harvesting devices such as photovoltaic cells are able to generate electricity. Increasing light absorption inside absorber materials becomes especially important in order to increase device efficiency. Moreover, for the past several decades, nanostructures have demonstrated their capabilities of both improving light management and reducing material consumption. In order to conduct efficient nanostructure design optimization, simulation with finite-difference time-domain (FDTD) method is utilized. With FDTD method, several nanostructures with varieties of applications were studied: the nanospike (NSP) amorphous silicon (a-Si) solar cells, the Polydimethylsiloxane (PDMS) nanocones as anti-reflection (AR) coating for cadmium telluride/ cadmium sulfide (CdTe/CdS) solar cells, photoelectrochemical water splitting with ultrathin hematite on NSP structures, etc. Intriguingly, FDTD simulation has the strength of clearly showing absorption properties inside nanostructures, which is critical for the purpose of solar energy harvesting. Moreover, geometrical design has been conducted to optimize the nanostructures for better device performance. Pitch of periodic structures and aspect ratio of nanostructures are two common parameters to tune for geometry optimization.

Date of Award	2015
Original language	English
Awarding Institution	The Hong Kong University of Science and Technology