Sputtering Deposited CuCrO₂ and CuCrO₂-ZnSnN₂ Heterojunctions

Area of Science:

• Materials Science
• Solid State Physics
• Renewable Energy

Background:

• Copper chromium oxide (CuCrO2) and zinc tin nitride (ZnSnN2) are promising materials for optoelectronic devices.
• Theoretical studies predict high photoelectric conversion efficiency for CuCrO2-ZnSnN2 heterojunctions (HJs).
• Experimental investigation of these heterojunctions is lacking.

Purpose of the Study:

• To experimentally fabricate and characterize CuCrO2-ZnSnN2 heterojunctions.
• To explore the effect of sputtering power on the properties of CuCrO2 thin films and the resulting HJs.
• To assess the photoelectric performance of the fabricated heterojunctions.

Main Methods:

• Fabrication of CuCrO2 thin films and p-CuCrO2-n-ZnSnN2 heterojunctions using sputtering.
• Varying sputtering power of the Cu-Cr alloy target while keeping other parameters constant.
• Characterization using current density-voltage (J-V) measurements under dark and illuminated conditions.

Main Results:

• As-deposited CuCrO2 films were amorphous with CuCrO2 as the major phase, exhibiting p-type conductivity and a band gap of 3.64-3.84 eV.
• ZnSnN2 films showed wurtzite structure and n-type conductivity.
• All fabricated HJs exhibited rectification, with photo-induced current observed only for samples deposited at 40 W and 50 W.
• The HJs fabricated at 40 W demonstrated the lowest shunt conductance, saturation current density, and trap density.

Conclusions:

• Fabrication conditions significantly influence the properties and performance of CuCrO2-ZnSnN2 heterojunctions.
• The study provides the first experimental evidence of photoelectric properties in CuCrO2-ZnSnN2 heterojunctions.
• Optimized sputtering power is crucial for achieving efficient photoelectric conversion in these devices.