【Device Papers】Inkjet Printing Fabrication of Ga₂O₃ Detectors and Optimization of MSM Structures

      Researchers from the Guangdong University of Technology have published a dissertation titled " Inkjet Printing Fabrication of Ga₂O₃ Detectors and Optimization of MSM Structures " in Materials Research and Application.

Abstract

      Solar-blind ultraviolet （UV） communication technology， operating within the 200—280 nm wavelength range， exhibits low background noise characteristics due to strong solar radiation absorption by the ozone layer in this band. This feature endows it with significant application value in military early warning， deep-space exploration， and power grid security monitoring. Gallium oxide （Ga₂O₃）， an ultra-wide bandgap semiconductor material， possesses intrinsic response characteristics to the solar-blind UV band， making it a research hotspot for solar-blind UV detectors. However， traditional Ga₂O₃ thin-film fabrication techniques， such as chemical vapor deposition， radio frequency magnetron sputtering， and molecular beam epitaxy， face challenges including high-temperature and high-vacuum requirements， as well as difficulties in achieving uniform large-area films. Inkjet printing technology， with advantages of low cost， high efficiency， and the ability to produce large-area devices， offers a new approach for fabricating Ga₂O₃-based photodetectors. Nevertheless， conventional planar metal-semiconductor-metal （MSM） electrode structures are prone to short-circuiting during the inkjet printing process， limiting its large-scale applications. This study proposes a three-layer sandwich-like MSM electrode structure， compsed of a single electrode， a Ga₂O₃ film， and another single electrode. This innovative design effectively addresses the short-circuiting issue in inkjet printing process while overcoming physical spacing limitations of traditional planar MSM electrodes. Experimental results demonstrate that detectors based on three-dimensional MSM structure exhibit excellent photoelectric performance at the 254 nm wavelength， with a photocurrent of 2.8×10^-6 A， responsivity of 482.7 A W^-1， detectivity of 6.9×10¹⁴ Jones， and an external quantum efficiency as high as 2.3×10³%. Moreover， the inkjet printing technique enables full-process detector fabrication， simplifying production process and reducing costs. This provides a new method for the efficient and low-cost fabrication of Ga₂O₃-based solar-blind UV detectors. The research innovation lies in introducing a disruptive three-dimensional MSM electrode structure， which effectively solves the short-circuiting problem in inkjet printing and enhances the performance and integration of MSM electrodes. Additionally， the full-process fabrication of detectors， including electrode pattern printing and Ga₂O₃ film printing， is realized through inkjet printing， significantly simplifying the production process. This study offers theoretical and technical support for the large-scale production and practical applications of Ga₂O₃-based solar-blind UV detectors，holding important scientific significance and application value.

LINK：

http://mra.ijournals.cn/clyjyyy/article/abstract/202504010?st=search