Nanowire array photovoltaics: Radial disorder versus design for optimal efficiency

TL;DR

This paper investigates how radial disorder in nanowire arrays can enhance solar cell efficiency, revealing the physical mechanisms and guiding the design of more effective photovoltaic structures.

Contribution

It introduces a semi-analytic method to understand and optimize nanowire array designs for higher efficiency, surpassing random arrangements.

Findings

Disordered nanowire arrays achieve higher efficiency than uniform structures.

Optimal array design yields an efficiency of 23.75%.

Disorder enhances light absorption and collection.

Abstract

Solar cell designs based on disordered nanostructures tend to have higher efficiencies than structures with uniform absorbers, though the reason is poorly understood. To resolve this, we use a semi-analytic approach to determine the physical mechanism leading to enhanced efficiency in arrays containing nanowires with a variety of radii. We use our findings to systematically design arrays that outperform randomly composed structures. An ultimate efficiency of 23.75% is achieved with an array containing 30% silicon, an increase of almost 10% over a homogeneous film of equal thickness.