Ultrahigh-Responsivity, Rapid-Recovery, Solar-Blind Photodetector Based on Highly Nonstoichiometric Amorphous Gallium Oxide

• DOI: 10.1021/acsphotonics.7b00359
• Publication Date: 2017-08-09T19:15:04Z
• Authors: Ling-Xuan Qian; Ze-Han Wu; Yi-Yu Zhang; P. T. Lai; Xing-Zhao Liu; Yan-Rong Li
• Keywords: 0103 physical sciences; 01 natural sciences

Recently, Ga2O3-based, solar-blind photodetectors (PDs) have been extensively studied for various commercial and military applications. However, to date, studies have focused only on the crystalline phases, especially β-Ga2O3, and the crystalline quality must be carefully controlled because of its strong impact on device characteristics. Based on previous reports, amorphous-semiconductor-based PDs can also be expected to exhibit excellent photodetection characteristics. In this work, amorphous gallium oxide thin films were deposited by radio frequency (RF) magnetron sputtering, and the metal–semiconductor–metal (MSM) PD was fabricated and compared with a β-Ga2O3 film prepared side-by-side as the control sample. The as-sputtered film possessed a high density of defects, including structural disorders, oxygen vacancies, and likely, dangling bonds, resulting in record-high responsivity (70.26 A/W) for a thin-film-type gallium oxide PD due to a high internal gain and the contribution of extrinsic transitions ...