A Sensitive Lead-Free Perovskite Photodetector for Self-Powered Blue Light Hazard Detection Application

The detection of blue light hazard for artificial illuminants has become a challenging issue. In this work, a self-powered narrowband photodetector based on lead-free perovskite Cs2AgBiBr6 for low-toxicity blue light hazard detection has been reported. Under zero bias, the responsivity and specific detectivity at response peak of 450 nm can reach 0.327 A/W and
${2}.{8}\times {10} ^{{10}}$
Jones, respectively. In visible light, the photodetector is only sensitive to blue light with a rejection ratio (450/510 nm) of 28.4, effectively suppressing the influence of other visible light without filters. Then an error factor is introduced to establish a relationship between the blue light weighted radiance and photocurrent. By integrating with the back-end circuit, a portable detection system is demonstrated, which can smartly evaluate the blue light hazard level of artificial illuminants. We believe that such highly sensitive and lead-free features render it a promising candidate for human eyes protection in the field of green healthcare.