Enhanced solar-blind responsivity of photodetectors based on cubic MgZnO films via gallium doping

Xiuhua Xie,Dezhen Shen,Dongxu Zhao,Chongxin Shan,Hongyu Chen,Binghui Li,Shuangpeng Wang,Zhenzhong Zhang,Mingming Jiang

doi:10.1364/oe.22.000246

Abstract

We report on gallium (Ga) doped cubic MgZnO films, which have been grown by metal organic chemical vapor deposition. It was demonstrated that Ga doping improves the n-type conduction of the cubic MgZnO films. A two-orders of magnitude enhancement in lateral n-type conduction have been achieved for the cubic MgZnO films. The responsivity of the cubic MgZnO-based photodetector has been also enhanced. Depletion region electric field intensity enhanced model was adopted to explain the improvement of quantum efficiency in Ga doped MgZnO-based detectors.

Highlights

Ultraviolet C (UVC, 100–280 nm) is a part of absent solar radiation at the Earth’s surface, due to absorption in the ozonosphere [1]
By employing Triethylgallium as the n-type dopant source, gallium (Ga) doped cubic MgZnO films have been grown by metal organic chemical vapor deposition (MOCVD)
Depletion region electric field intensity (EFI) enhanced model was adopted to explain the improvement of quantum efficiency (η) in Ga doped MgZnO-based detectors

Summary

Introduction

Ultraviolet C (UVC, 100–280 nm) is a part of absent solar radiation at the Earth’s surface, due to absorption in the ozonosphere [1]. For the cubic MgZnO based detectors, the gain mechanism is still not controllable, because of the ultra-high resistivity of the as grown films [24,25,26]. This is an obstacle that hampers the realization of high-performance solar-blind photodetectors. By employing Triethylgallium as the n-type dopant source, gallium (Ga) doped cubic MgZnO films have been grown by metal organic chemical vapor deposition (MOCVD). It was demonstrated through electrical, optical, and structural studies that Ga doping improves the n-type conduction of the cubic MgZnO films. Depletion region electric field intensity (EFI) enhanced model was adopted to explain the improvement of quantum efficiency (η) in Ga doped MgZnO-based detectors

Experiments and results discussion

Theoretical modeling and simulation

Conclusion