Charge Sampling Photodetector Based on van der Waals Heterostructures

摘要

Photodetector arrays are key component in image sensors. Charge-coupleddevices (CCD) based photodetection is widely used due to their high resolution,large sensitivity, and low noise. However, the complex device structure, destructiveand sequential readout method are primary concerns in expanding itsapplication scenarios. Here, a charge sampling photodetector (CSP) based onfully 2D absorption/dielectric/readout van der Waals heterostructures (vdWs) isreported. Photo-charges generated in the absorption layer are stored in a potentialwell of the vdWs, which enables weak signal detection and imaging afterthe charge integration process. A stacked transistor in the readout layer thennondestructively maps out the collected charges in a random-access mannerwith high fill factor. With a properly engineered absorption layer, CSP canrealize broadband detection from visible to mid-IR range at room temperatureand low operation voltage. Our device combines the advantages of CCD andcomplementary metal-oxide-semiconductor image technology, which exemplifiesa promising candidate for next-generation photodetectors.