Solar‐Blind Ultrathin Sn‐Doped Polycrystalline Ga2O3 UV Phototransistor for Normally Off Operation. Issue 5 (23rd March 2022)

• Record Type: Journal Article
• Authors: Yoon, Youngbin; Hwang, Wan Sik; Shin, Myunghun
• Is Part Of: Advanced photonics research. Volume 3:Issue 5(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-03-23
• Subjects: deep ultraviolet -- β-Ga2O3 semiconductors -- phototransistors -- solar blindness -- ultrawide bandgap; Photonics -- Periodicals; 621.36505
• DOI: 10.1002/adpr.202100316
• Languages: English
• ISSNs: 2699-9293

Abstract

Abstract : Deep ultraviolet (DUV) photodetectors (PDs) based on ultrawide bandgap β ‐Ga2 O3 have great potential for aerospace, military, and civilian applications, especially because of their inherent solar blindness. An 8 nm thick Sn‐doped polycrystalline β ‐Ga2 O3 semiconductor is used as the channel material for a solar‐blind PD in this study. The β ‐Ga2 O3 channel is fully depleted by upward bending of the energy band owing to the work function difference between the highly p‐type Si (gate electrode) and β ‐Ga2 O3, resulting in normally off behavior with a positive threshold voltage under dark conditions. The normally off behavior is beneficial for simplicity of the gate‐driver circuitry and low power consumption under standby conditions. The fully depleted 8 nm thick polycrystalline β ‐Ga2 O3 exhibits high‐performance DUV detection capability of light at 215 nm: a low dark current of 29.3 pA and high photo‐to‐dark‐current ratio of ≈10 4 at zero gate voltage. This fully depleted n‐type β ‐Ga2 O3 semiconductor with a wafer‐scale substrate can expedite the realization of high‐performance and low‐power‐consumption solar‐blind PDs. Abstract : Herein, an 8‐nm‐thick Sn‐doped polycrystalline β ‐Ga2 O3 semiconductor is used as the channel material for a solar‐blind photodetector. The β ‐Ga2 O3 channel is fully depleted, resulting in normally off behavior with a positive threshold voltage under dark conditions. The 8‐nm‐thick Sn‐doped polycrystalline β ‐Ga2 O3 photodetector exhibits a low dark current of 29.3 pA and hence a high photo‐to‐dark‐current ratio at zero gate voltage.