【International Papers】Ultraviolet Photodetector Based on a Beta-Gallium Oxide/Nickel Oxide/Beta-Gallium Oxide Heterojunction Structure

Researchers from the Department of Information Technology and Electronics, Faculty of Science and Engineering, Ishinomaki Senshu University have published a dissertation titled " Ultraviolet Photodetector Based on a Beta-Gallium Oxide/Nickel Oxide/Beta-Gallium Oxide Heterojunction Structure " in Optoelectronic Sensors.

Abstract

In this paper, an n–p–n structure based on a β-Ga₂O₃/NiO/β-Ga₂O₃ junction was fabricated. The device based on the β-Ga₂O₃/NiO/β-Ga₂O₃ structure, as an ultraviolet (UV) photodetector, was compared with a p–n diode based on a NiO/β-Ga₂O₃ structure, where it showed rectification and 10 times greater responsivity and amplified the photocurrent. The reverse current increased in proportion to the 1.5 power of UV light intensity. The photocurrent amplification was related to the accumulation of holes in the NiO layer given by the heterobarrier for holes from the NiO layer to the β-Ga₂O₃ layer. Moreover, the device could respond to an optical pulse of less than a few microseconds.

Figure 1. Cross-sectional structure of the device and a photograph of its top view. Three electrodes are represented by E, B, and C.

Figure 2. X-ray diffraction patterns (2θ–ω scan) of the β-Ga₂O₃ and NiO layers formed on the (001) β-Ga₂O₃ substrate.

Paper Link：https://doi.org/10.3390/s23198332