Electrode‐Dependent Electrical Properties of Detection‐Band Tunable Ultraviolet Photodetectors Based on Ga2O3/GaN Heterostructures. Issue 15 (7th June 2021)

• Record Type: Journal Article
• Authors: Li, Guanqi; Tang, Ruifan; Gao, Na; Li, Cheng; Li, Jinchai; Huang, Kai; Kang, Junyong; Zhang, Rong
• Is Part Of: Physica status solidi. Volume 218:Issue 15(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-06-07
• Subjects: Ga2O3 -- heterostructures -- schottky barrier -- ultraviolet photodetectors; Solid state physics -- Periodicals; Solids -- Industrial applications -- Periodicals; 530.41
• DOI: 10.1002/pssa.202100166
• Languages: English
• ISSNs: 1862-6300

Abstract

Abstract : The polycrystal Ga2 O3 on GaN was realized by high‐temperature oxidization of the GaN films with oxidation time 1 and 10 h, and the metal‐semiconductor‐metal photodetectors based on the Ga2 O3 /GaN heterostructure were fabricated by using Ti and Au metal electrodes. A comparative study of different electrodes and oxidation time on the performance of ultraviolet photodetector is performed. Among the devices prepared by 1 h oxidation, it is found that the device fabricated with Au electrode shows a lower dark‐current and higher photocurrent than the one with Ti electrode. This is mainly due to the higher Schottky barrier height of sample with Au electrode. As for the device that experienced 10 h oxidation with Au electrode, the solar‐blind responsivity with the full width at half maxima of 12 nm was obtained, which can be attributed to thicker Ga2 O3 film. The devices exhibit excellent performance, including low dark‐current and satisfactory responsivity, even under ultra‐weak signal. The authors attribute these excellent properties to the Ga2 O3 film, as it has a large grain size and a porous structure. The results provide a simple method that is low‐cost and high‐output with large‐area production of high‐performance ultraviolet photodetectors. Abstract : Herein, metal–semiconductor–metal UV photodetectors (UV PDs) are prepared using Ga2 O3 /GaN heterostructures with different thicknesses and different electrodes. The devices show different photocurrent, dark current, and photoresponse spectra which is mainly related to Ga2 O3 thickness and electrode selection. These findings provide a way to optimize Ga2 O3 /GaN heterostructure‐based UV PDs.