Monolithic Tandem Multicolor Image Sensor Based on Electrochromic Color-Radix Demultiplexing

Adv Mater. 2021 Sep;33(35):e2102725. doi: 10.1002/adma.202102725. Epub 2021 Jul 23.

Abstract

Optical data acquisition has been set as one of the milestones to testify the developments aimed at harnessing the full potential of the spatial and temporal data processing capabilities of the advanced semiconductor technology. A highly promising approach to drive the level of acquisition beyond the current technological node is the vertical integration of multiple photodetectors. However, vertical integration so far requires the same level of circuit complexity as lateral integration from the incapability of monolithic integration. Here, an electrochromic device architecture is introduced that enables realization of a monolithic tandem multicolor photodetector. The device, composed of vertically stacked p-type and n-type graphene barristors, is demonstrated to be capable of regulating the balanced charge transport under any desired illumination wavelengths. It exhibits variable anti-ambipolar charge transport behavior, which yields sensitive voltage-controlled photoconductive gain spectra. These electrical behaviors are utilized to fabricate an optoelectronic logic sensor that can demultiplex the desired color coordinate or wavelength in the constituent array with high color accuracy.

Keywords: filter-less approaches; monolithic tandem; multicolor image sensor; photodetectors; vertical integrations.