Modeling of heterojunction photovoltaic cells based on ZnO nanowires array and earth-abundant cuprous oxide absorbers

TL;DR

This paper models heterojunction solar cells using ZnO nanowires and Cu2O absorbers, showing potential efficiencies up to nearly 20% and emphasizing the importance of device design and material quality.

Contribution

It provides a theoretical framework for designing ZnO/Cu2O nanowire-based solar cells and analyzes how geometry and material states affect performance.

Findings

Potential efficiency of 19.7% with optimal design

Efficiency range from 12% to 22% depending on material quality

Device design critically influences solar cell performance

Abstract

As a potential solution for low-cost efficient solar cells, radial junctions consisting of ZnO nanowires arrays embedded in Cu2O thin films have been theoretically modeled. Calculations have been performed to explore the geometric dependence of performance of such wire-based solar cells. By properly setting material properties and cell dimensions, a reasonable power conversion efficiency of 19.7% can be expected in a material with 2 {\mu}m minority carrier diffusion length. The detrimental effects of bulk, interface and contact-related states on solar cell performance have also been studied, from which the efficiencies between ~22% and ~12% for a series of materials, ranging from optimal to seriously poor-quality, are extracted. The findings suggest that rational device design plays a crucial role in implementing efficient Cu2O/ZnO wire radial junction solar cells.