Zihan Zhang , Anzhen Zhang , Qiyi Wan , Rui Qin , Xinyue Zhang , Weiwei Cao , Jiuhong Wang
{"title":"Optimized oxygen flux in sputtering amorphous Ga2O3 thin films enables high-performance solar-blind UV photodetectors","authors":"Zihan Zhang , Anzhen Zhang , Qiyi Wan , Rui Qin , Xinyue Zhang , Weiwei Cao , Jiuhong Wang","doi":"10.1016/j.vacuum.2025.114748","DOIUrl":null,"url":null,"abstract":"<div><div>This study systematically investigates the effect of oxygen flux on the optical properties of amorphous gallium oxide (a-Ga<sub>2</sub>O<sub>3</sub>) thin films deposited on SiO<sub>2</sub>/Si substrates via RF magnetron sputtering. Through comprehensive material characterization and device performance analysis, we elucidate the correlation between defect evolution (including oxygen vacancies and other intrinsic defects) and the resulting optoelectronic responses. Our findings reveal that oxygen vacancy concentration mainly influences the optical band gap. Although increasing oxygen flux significantly reduces the oxygen vacancy concentration, the overall defect density exhibits a nonlinear trend because additional defect states are concurrently introduced. Consequently, the device performance exhibits a nonlinear dependence on oxygen flux. The detector prepared under moderate oxygen flux conditions exhibits an ultra-high light-dark current ratio of up to 4 × 10<sup>5</sup> and a low dark current at the pA level. Furthermore, these devices demonstrate rapid response kinetics, with a rise time of 28.9 ms and a fall time of 0.9 ms. These changes are attributed to the interplay between defects and material properties. This study provides critical insights into the process development of high-performance a-Ga<sub>2</sub>O<sub>3</sub> solar-blind UV photodetectors.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"242 ","pages":"Article 114748"},"PeriodicalIF":3.9000,"publicationDate":"2025-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Vacuum","FirstCategoryId":"88","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0042207X25007389","RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MATERIALS SCIENCE, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
This study systematically investigates the effect of oxygen flux on the optical properties of amorphous gallium oxide (a-Ga2O3) thin films deposited on SiO2/Si substrates via RF magnetron sputtering. Through comprehensive material characterization and device performance analysis, we elucidate the correlation between defect evolution (including oxygen vacancies and other intrinsic defects) and the resulting optoelectronic responses. Our findings reveal that oxygen vacancy concentration mainly influences the optical band gap. Although increasing oxygen flux significantly reduces the oxygen vacancy concentration, the overall defect density exhibits a nonlinear trend because additional defect states are concurrently introduced. Consequently, the device performance exhibits a nonlinear dependence on oxygen flux. The detector prepared under moderate oxygen flux conditions exhibits an ultra-high light-dark current ratio of up to 4 × 105 and a low dark current at the pA level. Furthermore, these devices demonstrate rapid response kinetics, with a rise time of 28.9 ms and a fall time of 0.9 ms. These changes are attributed to the interplay between defects and material properties. This study provides critical insights into the process development of high-performance a-Ga2O3 solar-blind UV photodetectors.
期刊介绍:
Vacuum is an international rapid publications journal with a focus on short communication. All papers are peer-reviewed, with the review process for short communication geared towards very fast turnaround times. The journal also published full research papers, thematic issues and selected papers from leading conferences.
A report in Vacuum should represent a major advance in an area that involves a controlled environment at pressures of one atmosphere or below.
The scope of the journal includes:
1. Vacuum; original developments in vacuum pumping and instrumentation, vacuum measurement, vacuum gas dynamics, gas-surface interactions, surface treatment for UHV applications and low outgassing, vacuum melting, sintering, and vacuum metrology. Technology and solutions for large-scale facilities (e.g., particle accelerators and fusion devices). New instrumentation ( e.g., detectors and electron microscopes).
2. Plasma science; advances in PVD, CVD, plasma-assisted CVD, ion sources, deposition processes and analysis.
3. Surface science; surface engineering, surface chemistry, surface analysis, crystal growth, ion-surface interactions and etching, nanometer-scale processing, surface modification.
4. Materials science; novel functional or structural materials. Metals, ceramics, and polymers. Experiments, simulations, and modelling for understanding structure-property relationships. Thin films and coatings. Nanostructures and ion implantation.