Miniaturized spectrometer with intrinsic long-term image memory

Abstract

Miniaturized spectrometers have great potential for use in portable optoelectronics and wearable sensors. However, current strategies for miniaturization rely on von Neumann architectures, which separate the spectral sensing, storage, and processing modules spatially, resulting in high energy consumption and limited processing speeds due to the storage-wall problem. Here, we present a miniaturized spectrometer that utilizes a single SnS₂/ReSe₂ van der Waals heterostructure, providing photodetection, spectrum reconstruction, spectral imaging, long-term image memory, and signal processing capabilities. Interface trap states are found to induce a gate-tunable and wavelength-dependent photogating effect and a non-volatile optoelectronic memory effect. Our approach achieves a footprint of 19 μm, a bandwidth from 400 to 800 nm, a spectral resolution of 5 nm, and a > 10⁴s long-term image memory. Our single-detector computational spectrometer represents a path beyond von Neumann architectures.

Recent studies have reported miniaturized spectrometers based on van der Waals heterostructures. Here, the authors demonstrate multifunctional SnS₂/ReSe₂ heterojunction spectrometers providing photodetection, spectrum reconstruction, spectral imaging, long-term image memory, and signal processing capabilities.