Bolometric Effect in Bi₂ O₂ Se Photodetectors

Area of Science:

• Materials Science
• Condensed Matter Physics
• Optoelectronics

Background:

• Bismuth oxychloride (Bi2O2Se) is recognized as a promising photosensitive material for optoelectronic applications.
• Previous research primarily attributed the photodetection mechanism in Bi2O2Se to a photoconductive regime.

Purpose of the Study:

• To investigate and confirm the presence of the bolometric effect in Bi2O2Se-based photodetectors.
• To elucidate the underlying mechanisms responsible for the unique photoresponse of Bi2O2Se.

Main Methods:

• Multiwavelength photoresponse measurements to observe coexistence of effects.
• Microscale local heating experiments to validate findings.
• Real-time temperature tracking of Bi2O2Se photodetectors under light excitation.

Main Results:

• The bolometric effect was discovered and confirmed in Bi2O2Se photodetectors.
• A coexistence of both photoconductive and bolometric effects was observed.
• High performance metrics were achieved, including a high temperature coefficient of resistance (-1.6% K⁻¹), bolometric coefficient (-31 nA K⁻¹), and bolometric responsivity (>320 A W⁻¹).

Conclusions:

• The unique photoresponse is potentially linked to hot electron behavior during temperature increases.
• This research presents a novel approach for developing bolometric photodetectors utilizing Bi2O2Se layered materials.