Solution-processed ZnCdO alloy thin films with high mobility and phase stability

Abstract

Alloying wide-bandgap ZnO and high-mobility CdO provides a versatile platform for simultaneous tuning electrical transport and optical properties of oxide semiconductors for specific device applications. Here, Zn1-xCdxO alloy thin films (x = 0-0.15, 0.85-1) were synthesized using a sol-gel spin-coating process. Wurtzitestructured Zn-rich alloys (x <0.15) exhibit wide bandgaps of 2.9-3.3 eV and high thermal stability. On the other hand, rock-salt Cd-rich alloys (x > 0.85) demonstrate excellent electrical transport properties. In particular, mobility exceeding 100 cm(2)/Vs and resistivity on the order of 10(-4) Omega cm are achieved after annealing at 500 degrees C for x > 0.9. These transport characteristics are comparable to those reported for high-vacuum physical vapor deposition-grown Zn1-xCdxO films. This work shows that the sol-gel processing provides a scalable and costeffective route to high-mobility, thermally stable Zn1-xCdxO alloys, highlighting their potential as transparent conductors and carrier-transport layers for optoelectronic devices.