• Rapenne, Laetitia
• Muñoz-Rojas, David
• Bellet, Daniel
• Chichignoud, Guy
• Huerta, César Arturo Masse De La
• Sekkat, Abderrahime
• Kaminski-Cachopo, Anne
• Nguyen, Viet Huong

Abstract

u 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.

Topics

• impedance spectroscopy
• mobility
• thin film
• copper
• defect
• Raman spectroscopy
• atomic layer deposition
• p-type semiconductor