Detailed balance limit of silicon nanowire and nanohole array solar cells

In this proceeding, we use optical modeling and detailed balance analysis to predict the limiting efficiency of nanostructured silicon solar cells based on vertically-aligned nanowire and nanohole arrays. We first use the scattering matrix method to study broadband optical absorption. By incorporating the calculated optical absorption into a detailed balance analysis, we obtain the limiting short circuit current, open circuit voltage, and power conversion efficiency of nanowire and nanohole solar cells. Results show that optimized nanowire and nanohole arrays of 2.33 microns in height have 83% and 97% higher power conversion efficiencies than a thin film with the same height, respectively. Furthermore, we find that the limiting power conversion efficiency is mainly determined by the short circuit current density, which is proportional to the broadband optical absorption.