Sensitively switchable visible/infrared multispectral detection and imaging based on a tandem perovskite device

Abstract

Multispectral detection and imaging facilitate advances in target identification; for example, the switchable functionality of sensing visible photons and sensing near-infrared photons in the eyes of some vertebrate species provide visual sensitivity beyond the range of human vision. In this work, a single sensor device is constructed with stacking solution-processed MAPbI₃ and MA_0.5FA_0.5Pb_0.5Sn_0.5I₃ in opposite polarity for the multispectral detection of visible and NIR photons. With applied bias modulating built-in potential, the sensing response is tunable, while the good ambipolar carrier transport and high trap tolerance in perovskite films ensure high performance. As a result, the selective sensing toward visible photons from 350–800 nm and NIR photons from 700–1000 nm is achieved in a single photodetector under −0.3V and 0.5 V, respectively, with a high on/off ratio of ∼10⁴, a relatively low optical crosstalk of −70 dB, and specific detectivity of over 10¹² Jones. Moreover, the high mode-switching rate of 1000 Hz in altering the visible and NIR sensing mode and the high −3 dB bandwidth of ∼50 kHz enable our solution-processed perovskite-based multispectral photodetector to be recognized as an advanced technique for the fast and sensitive target multispectral imaging and identification.