Ultra-Fast Gallium Oxide Solar-Blind Photodetector with Novel Thermal Pulse Treatment

Area of Science:

• Materials Science
• Optoelectronics
• Semiconductor Physics

Background:

• Gallium oxide (Ga₂O₃) is a promising material for solar-blind photodetectors (SBPDs).
• A key challenge is the "Response Speed (RS) dilemma," limiting simultaneous high responsivity and fast response.
• Existing solutions for segregated carrier generation and transport are scarce.

Purpose of the Study:

• To develop a novel method for improving Ga₂O₃-based SBPD performance.
• To address the "RS dilemma" by creating spatially segregated carrier channels.
• To demonstrate enhanced responsivity and response speed in Ga₂O₃ SBPDs.

Main Methods:

• A novel thermal pulse treatment (TPT) was employed on Ga₂O₃ films.
• TPT induced a vertically stratified crystalline structure and controlled oxygen vacancy (V_O) distribution.
• Extensive characterizations and Technology Computer-Aided Design (TCAD) simulations were performed.

Main Results:

• TPT successfully created a stratified V_O profile in Ga₂O₃ films.
• TCAD simulations confirmed V_O stratification's role in enhancing responsivity (R_λ) and response speed.
• The TPT-processed SBPD achieved a maximum R_λ of 312.6 A W^-1 and a decay time of 40 µs.

Conclusions:

• The TPT method effectively resolves the "RS dilemma" in Ga₂O₃ SBPDs.
• Stratified V_O is crucial for simultaneously improving responsivity and response speed.
• The developed SBPDs show significant potential for solar-blind imaging and sensing applications.