Nanowire array photovoltaics: Radial disorder versus design for optimal efficiency

• Published in: Applied physics letters Vol. 101; no. 17
• Main Authors: Sturmberg, C P, Dossou, Kokou B, Botten, Lindsay C, Asatryan, Ara A, Poulton, Christopher G, McPhedran, Ross C, Sterke, Martijn de
• Format: Journal Article
• Language: English
• Published: 22-10-2012
• Subjects: Arrays; Design engineering; Nanocomposites; Nanomaterials; Nanostructure; Nanowires; Optimization; Photovoltaic cells; Solar cells
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.4761957

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.