Monolithically Integrated PbS Colloidal Quantum Dot Photodetector Crossbar Array for Short-Wavelength Infrared Imaging

Monolithically integrated pixels, with stacked PbS colloidal quantum dot (CQD) photodiodes and organic blocking diodes, are developed as the building block for constructing a short-wavelength infrared (SWIR) crossbar imaging array. Arising from the back-to-back stacked configuration and a favorable energy level alignment, holes are blocked from the photodiode at zero and forward biases, which results in the normally-OFF behavior of the pixels. Based on such device characteristics, the monolithically integrated pixels can effectively suppress electrical crosstalk under illumination in the crossbar array and consume nearly zero standby power. Furthermore, an 8 x 8 crossbar imaging array with both high imaging quality and low power consumption is achieved, which features as a high-performance visible-SWIR imaging sensor.