Highly Sensitive Ga2O3-Face Tunnel Field Effect Phototransistor for Deep UV Detection

In this article, a Technology Computer-Aided Design (TCAD)-based study has been done for gallium oxide (Ga ₂ O ₃ ) gated UV phototransistor with face tunneling architecture and magnesium silicide (Mg ₂ Si) substrate using ATLAS-2-D device simulator, in which Ga ₂ O ₃ has been used as a photoabsorber layer over the complete channel. The photon absorption inside the Ga ₂ O ₃ has been utilized to modulate the silicon channel conduction (tunneling at the source channel junction), where the advantage of face tunneling over the conventional tunnel field-effect transistor (TFET) architectures has been shown. The device operation has been studied in the wavelength spectrum of deep UV (DUV) (solar blind) and outside this range to analyze the application of the proposed architecture for DUV radiation detection and rejecting others. From the dark and illuminated characterization, transient response, and spectral response, Ga ₂ O ₃ of thickness 50 nm is the best concluded candidate with a response time of 11.5 ms, sensitivity of $1.1\times 10^{7}$ , responsivity of $3.59\times 10^{4}$ A/W, and detectivity of $4.15\times 10^{15}$ Jones, which makes it a suitable candidate for its application as DUV photodetector.