P-n homojunction based on Bi doped p-type ZnO and undoped n-type ZnO for optoelectronic application in yellow-red region of visible spectrum

Abstract

Fabrication of zinc oxide (ZnO) based optoelectronic devices requires stable and reproducible p-type nanostructures. Keeping this fact in view, high-quality Bismuth (Bi) doped p-type ZnO thin films have been deposited on the n-Si substrate using sol-gel spin coating technique. Hall effect and hot point probe measurement confirm that deposited Bi doped ZnO film has p-type conductivity with a resistivity of 0.82 Ω-cm, carrier concentration of 1.1 × 1018 cm−3 and mobility of 6.9 cm2/ V-s at room temperature. A p-n homojunction has been fabricated by making use of this p-type ZnO and intrinsic n-type ZnO. The I-V characteristics of the fabricated p-n junction clearly show the rectifying nature. PL analysis reveals that the fabricated device exhibits deep level emission in yellow and red emission bands ascertaining its potential application in optoelectronics.