Self-powered all-quantum dot based broadband photodetectors for color imaging and heart rate monitoring

Self-powered broadband photodetectors (PDs) are crucial in various daily applications. However, traditional Si-based broadband PDs have limited responses in the infrared and ultraviolet spectra, hindering further development. To address this challenge, this work proposes self-powered all-quantum dot (QD) based broadband PDs. These PDs are integrated with SnO2 QDs/PbS-I QDs/PbS-EDT QDs, enabling broadband photodetection from 300 to 1000 nm. By adjusting the thickness of the SnO2 QD layer, these PDs exhibit high self-powered responsivity (401.8 mA W-1), high detectivity (4.8 x 1012 Jones), high EQE (62%), fast response speed (rise time 11.4 mu s; decay time 14.7 ms) and ultrahigh on/off ratio (1.4 x 104). These PDs can be used for long-distance color recognition imaging and human heartbeat monitoring. This study demonstrates the potential application of all-quantum dot PDs in the field of broadband photodetection. All-quantum dot based self-powered broadband (300-1000 nm) photodetectors (SnO2 QDs/PbS-I QDs/PbS-EDT QDs) were successfully fabricated, showing great potential in long-distance color recognition imaging and human heartbeat monitoring.