Photogating-enhanced photodetection in substrate-assisted borophene-graphene hybrids.

Area of Science:

• Materials Science
• Nanotechnology
• Optoelectronics

Background:

• Photodetectors (PDs) performance is often limited by underlying mechanisms.
• Photoconductive (PC) effects modulate conductivity directly, while photogating (PG) effects modulate photocurrent indirectly via trapped charges.
• Graphene-based PDs primarily utilize the PG effect, which can be substrate-dependent.

Purpose of the Study:

• To investigate the performance of hydrogenated borophene-based hybrid photodetectors.
• To understand the influence of substrates and photogating (PG) assistance on device performance.
• To elucidate the combined effects of PC and PG mechanisms in novel borophene/graphene heterostructures.

Main Methods:

• Fabrication of hybrid photodetectors using borophene and graphene on different substrates (SiO2/Si and PDMS).
• Characterization of device performance under 532 nm illumination, varying substrate conditions and PG assistance.
• Analysis of photocurrent modulation, responsivity, gain, detectivity, and response time.

Main Results:

• Borophene addition to graphene/SiO2/Si PDs significantly enhanced photocurrent via combined PC and PG effects.
• The champion device achieved high responsivity (7.88 × 10^3 A W^-1) and detectivity (1.74 × 10^14 Jones).
• Insulating PDMS substrates suppressed the PG effect, limiting photocurrent in borophene/graphene/PDMS devices.

Conclusions:

• Hydrogenated borophene effectively enhances photodetector performance by enabling synergistic PC and PG effects.
• The substrate plays a crucial role in modulating photogating efficiency.
• Borophene/graphene hybrid photodetectors on SiO2/Si exhibit superior optoelectronic properties and faster response times.