More than 3-mm-long carrier diffusion and strong absorption over the full solar spectrum in copper oxide and selenium composite film

TL;DR

This study presents a copper oxide and selenium composite film with exceptionally long carrier diffusion length and high broadband absorption, promising for solar energy applications.

Contribution

It introduces a novel nano/amorphous COS composite film with record carrier diffusion length and broad-spectrum absorption, fabricated via RF magnetron co-sputtering and annealing.

Findings

Carrier diffusion length of 3.147 mm in COS film

Average light absorptance of ~80% over 250-2500 nm

Potential application in solar cells and photo-electric devices

Abstract

Usually, single-crystal material has a longer carrier diffusion length due to fewer defects. Here, we report a nano/amorphous copper oxide and selenium (COS) composite film prepared by radio frequency magnetron co-sputtering of CuO and Se and post annealing. The photo-generated carriers in the COS film can diffuse very far (3.147 mm). Additionally, the COS film can strongly absorb light over the entire solar spectrum region (250-2500 nm) (average absorptance is ~80%). These results indicate that the COS composite is an excellent material and can be used in solar cells and other photo-electric devices.