Enhancement of hole mobility in high-rate reactively sputtered Cu2O thin films induced by laser thermal annealing

TL;DR

This study demonstrates that laser thermal annealing significantly improves hole mobility in high-rate sputtered Cu2O thin films, with detailed analysis of microstructural and optical property changes.

Contribution

It introduces a systematic laser annealing process to enhance hole mobility in Cu2O films deposited by high-rate sputtering, a novel approach for improving their electronic properties.

Findings

Hole mobility increased up to 24 cm2/Vs after LTA.

LTA affects microstructure, crystallinity, and optical band gap.

Temperature-dependent Hall measurements elucidate mobility enhancement mechanisms.

Abstract

In presented work, a reactive high-power impulse magnetron sputtering (r-HiPIMS) was used for high-rate deposition ( 170 nm/min) of Cu2O films. Films were deposited on a standard soda-lime glass (SLG) substrate at a temperature of 190C. As-deposited films exhibit poor hole mobility in the orders of 1 cm2/Vs. We have systematically studied the effect of laser thermal annealing (LTA) procedure performed using high-power infrared laser under different laser parameters (number of pulses, length of the pulse). We have found, LTA procedure could significantly enhance the hole mobility (up to 24 cm2/Vs in our case). We have also fitted the results of a temperature-dependent Hall measurement to clarify the mechanism of the reported increase in hole mobility. Moreover, we have discussed the effect of the LTA procedure on microstructure (crystallinity, surface morphology) and on the value of optical band gap.