High-Efficiency Cu₂O-Based Heterojunction Solar Cells Fabricated Using a Ga₂O₃Thin Film as N-Type Layer

Abstract

High-efficiency heterojunction solar cells consisting of a nondoped Ga 2 O 3 thin film as an n-type semiconductor layer and a p-type Cu 2 O sheet as the active layer as well as the substrate, prepared by thermally oxidizing a Cu sheet, are demonstrated. The use of an n-type Ga 2 O 3 thin film can greatly improve the performance of n-Ga 2 O 3 /p-Cu 2 O heterojunction solar cells. The highest efficiency of 5.38% was obtained in an Al-doped ZnO/Ga 2 O 3 /Cu 2 O heterojunction solar cell fabricated with an n-Ga 2 O 3 thin-film layer prepared at room temperature with a thickness of 75 nm by a pulsed laser deposition method.

Band offsets of n-type electron-selective contacts on cuprous oxide (Cu2O) for photovoltaics

“…2,3 Another promising material is Ga 2 O 3 , which offers near ideal electronic alignment. This alignment has led to the record-high open circuit voltages in thermally oxidized (0.8 V) 26 and electrochemically deposited (1.2 V) 5 Cu 2 O cells. The offset measured in the present study represents an increase over the previous measurement of À0.18 6 0.16 eV, 5 which is likely due to differences in surface preparation or deposition conditions.…”

Interface stoichiometry control to improve device voltage and modify band alignment in ZnO/Cu2O heterojunction solar cells

“…9 There are several challenges to making a Cu 2 O photovoltaic device, including an inability to dope the material, 2,10 its relatively low chemical stability compared to other oxides, 11 and a lack of suitable heterojunction partners due to an unusually small electron affinity. 12 We have focused on the low chemical stability, namely the fact that Cu 2 O is an especially reactive oxide due to its low enthalpy of formation…”

Molecular Precursor Method for Fabricating p-Type Cu2O and Metallic Cu Thin Films

“…Transparent metal oxide thin ilms of p-type semiconductors deposited directly on various substrates ofer several advantages in the design of heterojunctions with n-type oxide ilms for fabricating thin ilm devices [2,3]. Over the past years, the quest to obtain high-quality cuprous oxide ilms has fueled the development of many physical processing techniques including sputering, thermal oxidation, vacuum evaporation, molecular beam epitaxy, and electrodeposition [4][5][6][7][8][9].…”