A Study of Pyro-Phototronic Effect in ZnO/CdSe Colloidal Quantum Dots-Based Self-Powered Photodetectors

This article studies the pyro-phototronic effect in different colloidal quantum dots (CQDs) based on self-powered photodetectors. The impact of the transport layer, electrodes, and substrate on the pyrocurrent has been studied and it has been observed that the pyro-phototronic effect is dominant for Au-electrode in ITO-based devices while it is higher in Pd-electrode for Si-based devices. The study is performed using two sources namely UV and white light. The MoOx/Au-based device shows 70% of the pyro-current over the saturated photocurrent (
${{J}_{\text {py}}}/{{J}_{\text {ph}}}$
) with a rise time of 9.69 ms under white light illumination, best among the ITO-based devices. Si-based devices show an improvement of 93.94% over the photocurrent due to the involvement of the pyro-phototronic effect. The present work also proposes an equivalent circuit model for the self-powered photodetector incorporating the pyro-phototronic effect. Finally, a study of noise in different self-powered photodetectors is also presented.