High-performance layer-structured Si/Ga₂O₃/CH₃NH₃PbI₃ heterojunction photodetector based on a Ga₂O₃ buffer interlayer

Area of Science:

• Materials Science
• Optoelectronics
• Semiconductor Devices

Background:

• Organic-inorganic metal halide perovskites offer excellent optoelectronic properties for photodetectors (PDs).
• Gallium oxide (Ga2O3) serves as a buffer layer, mitigating recombination and improving passivation.
• Silicon (Si) is a widely used semiconductor material in optoelectronic applications.

Purpose of the Study:

• To investigate the effect of gallium oxide (Ga2O3) buffer layer thickness on the performance of silicon/perovskite photodetectors.
• To optimize the Ga2O3 layer thickness for enhanced photodetector characteristics.
• To explore the potential of a trilayer hybrid structure for high-performance optoelectronic devices.

Main Methods:

• Fabrication of a trilayer hybrid photodetector structure: Si/Ga2O3/CH3NH3PbI3.
• Systematic variation of the Ga2O3 interlayer thickness.
• Characterization of photodetector performance, including responsivity, detectivity, and response times.

Main Results:

• The photodetector performance, particularly responsivity, varied with Ga2O3 thickness, peaking at 300 nm.
• Optimized device achieved a responsivity of 7.2 mA/W and detectivity of 7.448×10^10 Jones.
• Fast rise (39 ms) and decay (1.7 ms) times were recorded, indicating efficient charge carrier dynamics.

Conclusions:

• A 300 nm Ga2O3 interlayer optimizes the performance of Si/Ga2O3/CH3NH3PbI3 photodetectors.
• The matched energy levels between Ga2O3 and perovskite contribute to the enhanced device performance.
• This hybrid structure presents a promising approach for fabricating advanced optoelectronic devices.