Structural and optoelectronic characteristics of β-Ga2O3 epitaxial films with Zn alloying and subsequent oxygen annealing. Issue 9 (21st February 2023)

• Record Type: Journal Article
• Authors: Sun, Xuan; Liu, Kewei; Chen, Xing; Hou, Qichao; Cheng, Zhen; Yang, Jialin; Ai, Qiu; Zhu, Yongxue; Li, Binghui; Liu, Lei; Shen, Dezhen
• Is Part Of: Journal of materials chemistry. Volume 11:Issue 9(2023)
• Page Start: 3227
• Page End: 3234
• Publication Date: 2023-02-21
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d2tc05204k
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : In this article, we have reported the fabrication of ∼7.5 at% Zn alloyed β-Ga2 O3 epitaxial films and their high performance solar-blind photodetectors. Abstract : Pure and ∼7.5 at% Zn alloyed β-Ga2 O3 epitaxial films were epitaxially grown by metal organic chemical vapor deposition choosing sapphire ( c -plane) as substrates, followed by 600 °C annealing in an oxygen atmosphere. We have characterized the structural, optical and electrical properties of the four prepared samples including as-grown pure β-Ga2 O3, annealed pure β-Ga2 O3, as-grown β-Ga2 O3 :Zn and annealed β-Ga2 O3 :Zn films in detail. Furthermore, solar-blind UV photodetectors with metal–semiconductor–metal structures fabricated from these epitaxial thin films have been demonstrated. A giant performance enhancement can be observed for β-Ga2 O3 photodetectors by Zn alloying and subsequent oxygen annealing. The device fabricated from the annealed β-Ga2 O3 :Zn film shows a low dark current of ∼3.7 × 10 −11 A, a high responsivity of 2.8 × 10 3 A W −1 and a high UV-vis rejection ratio of 5.6 × 10 5 at 10 V bias. And an ultra-high specific detectivity up to 5.9 × 10 16 cm Hz 1/2 W −1 (Jones) is observed. Such excellent photodetection performance of annealed Ga2 O3 :Zn devices can be explained by the donor compensation effect and the deep level trap removal effect by the introduction of Zn. Our findings contribute a roadmap for realizing high-performance Ga2 O3 -based solar-blind photodetectors, and provide a sturdy foundation for future applications.