Single cuprous oxide films synthesized by radical oxidation at low temperature for PV application

TLDR

The study investigates the synthesis of Cu₂O thin films by radical oxidation using N₂ plasma treatment and varying RF power at 500 °C. The films are produced by radical oxidation under N₂ plasma at low temperature, with RF power adjusted to control film growth. X‑ray diffraction shows Cu₂O films on c‑sapphire with a preferred (111) orientation; N₂ plasma treatment increases the bandgap from 1.69 to 2.42 eV, raises hole density, and lowers resistivity, yet overall device performance is poorer than films made without RF power; a ZnO/Cu₂O solar cell fabricated with 0 W RF power exhibits rectifying behavior with 0.02 % efficiency, 0.1 V open‑circuit voltage, and 24 % fill factor.

Abstract

Cuprous oxide (Cu(2)O) films synthesis by radical oxidation with nitrogen (N(2)) plasma treatment and different RF power at low temperature (500 °C) are studied in this paper. X-ray diffraction measurements show that synthesized Cu(2)O thin films grow on c-sapphire substrate with preferred (111) orientation. With nitrogen (N(2)) plasma treatment, the optical bandgap energy is increased from 1.69 to 2.42 eV, when N(2) plasma treatment time is increased from 0 min to 40 min. Although the hole density is increased from 10(14) to 10(15) cm(-3) and the resistivity is decreased from 1879 to 780 Ω cm after N(2) plasma treatment, the performance of Cu(2)O films is poorer compared to that of Cu(2)O using RF power of 0. The fabricated ZnO/Cu(2)O solar cells based on Cu(2)O films with RF power of 0 W show a good rectifying behavior with a efficiency of 0.02%, an open-circuit voltage of 0.1 V, and a fill factor of 24%.