Synchronous pressure-induced enhancement in the photoresponsivity and response speed of BiOBr

The development of the optoelectronics industry relies on the constant exploration and improvement of the photoelectric properties of functional materials. Responsivity and response speed are two key performance indicators of photodetectors. However, these parameters are often mutually suppressed, and ensuring both simultaneously is challenging. Herein, we developed a viable strategy to enhance the overall photodetection performance by applying pressure to improve both the photoresponsivity and the response speed of BiOBr simultaneously. The results showed that the responsivity of BiOBr at a pressure of 3.8 GPa was more than an order of magnitude higher than that measured at the initial pressure (0.2 GPa) under Xenon-light illumination. More importantly, the response speed of BiOBr was improved by almost an order of magnitude under 3.7 GPa and 405 nm laser illumination. The considerably enhanced photoresponsivity and photoresponse speed suggest that pressure effectively reduces the effective mass of carriers and promotes charge transfer between Bi-O atoms. Our findings reveal that comprehensive enhancement of optoelectronic properties in layered compounds can be achieved through pressure modulation of the electronic structure, providing a promising approach for materials design toward extraordinary properties.