Localized surface plasmon enhanced the photoresponse performance of Ga2O3 ultraviolet photodetectors

Abstract

The finite-difference time-domain method is employed in this study to analyze the influence of structural parameters on ultraviolet light absorption, and computer-aided design techniques are utilized to simulate the relevant characteristics of day-blind ultraviolet photodetectors. Two absorption structures are designed: metal nanoparticles-Ga₂O₃ and metal nanoparticles-Ga₂O₃-metal layers. The second structure achieves an absorption peak intensity of over 0.95 in the ultraviolet region. By investigating the electric field at the resonance peak, localized surface plasmon resonance is found to occur at the interface between the nanoparticles and Ga₂O₃, significantly enhancing the absorption of photon energy by the nanoparticles, which benefits the design of ultraviolet photodetectors. Furthermore, a gold nanoparticle Ga₂O₃ photodetector is designed, and it is discovered that the responsivity and external quantum efficiency of the gold nanoparticle Ga₂O₃ photodetector can reach up to 4.13 A/W and 2276 %, respectively, with the gold nanoparticles and gold absorption layer significantly improving the device's optoelectronic performance. The effect of Ga₂O₃ thickness on optoelectronic performance is also explored, showing that the detector's performance can be enhanced by adjusting the Ga₂O₃ thickness.