Open-air printing of Cu2O thin films with high hole mobility for semitransparent solar harvesters
Abderrahime Sekkat, Việt Hương Nguyễn, César Masse de La Huerta, Laëtitia Rapenne, Daniel Bellet, Anne Kaminski‐Cachopo, Guy Chichignoud, David Muñoz‐Rojas
Abstract
Abstract Cu 2 O is a promising p-type semiconductor for low-cost photovoltaics and transparent optoelectronics. However, low-cost and low-temperature fabrication of Cu 2 O films with good transport properties remains challenging, thus limiting their widespread adoption in devices. Here, we report Cu 2 O thin films of 20–80 nm thickness with hole mobility up to 92 cm 2 V −1 s −1 using atmospheric-pressure spatial atomic layer deposition at temperatures below 260 °C, from a copper (I) hexafluoro-2,4-pentanedionate cyclooctadiene precursor. Raman spectroscopy indicates the presence of copper split vacancies and shows that the high hole mobility can be correlated to a low concentration of shallow acceptor defects. The optical bandgap of deposited films can be tuned between 2.08 eV and 2.5 eV, depending on the deposition temperature. All-oxide semitransparent Cu 2 O/ZnO solar harvesters are fabricated, showing efficiency values comparable to devices that incorporate much thicker Cu 2 O layers. Our work provides a promising approach towards cost-efficient, all-oxide solar harvesters, and for other (opto)electronic devices.