Achieving 256 × 256‐Pixel Color Images by Perovskite‐Based Photodetectors Coupled with Algorithms

Abstract

Perovskites have been found with their exceptional optoelectronic properties that may bring new options to high‐performance cameras. However, the best images obtained by perovskite‐based photodetectors (PDs) have only 32 × 32 pixels, far below megapixels of camera images. In this study, a perovskite single‐PD color imaging prototype coupled with computation algorithms is fabricated, by which images with 256 × 256 pixels, whose quality has prevailed over those obtained by any perovskite‐based device so far are obtained. The technology shows its unique advantages by obtaining satisfying photographs, even when the PD is covered with frosted glass/moving smoke or facing a wall instead of the target, in addition to possessing some ability to resist ambient light interference. Moreover, a new Q factor is proposed to evaluate new‐material‐based PD for the imaging technology and prove its usability by comparing an atomic‐layer‐deposition (ALD)‐Al2O3 optimized CsBi3I10 PD and an unoptimized CsBi3I10 PD. Finally, the material choices are successfully extended to other types of perovskites, including photovoltaic MAPbI3 PD (structure: Spiro‐OMeTAD/MAPbI3/SnO2/FTO), ALD‐Al2O3 MAPbI3 PD, and ALD‐Al2O3 CsPbBr3 PD. The technology may bring an innovative approach to improve the performance of cameras and extend the application range of advanced functional materials.

Underwater Multispectral Computational Imaging Based on a Broadband Water-Resistant Sb2Se3 Heterojunction Photodetector

“…Fortunately, single-photodetector computational imaging (also named as ghost imaging or single-pixel imaging in some field), as a computational imaging technology that has only been developed for a decade, , exhibits excellent antiscattering underwater imaging capability, so it has attracted a significant interest in the field of underwater imaging. − In contrast to a commercial silicon-based charge-coupled device (CCD) and complementary metal–oxide–semiconductor (CMOS) cameras, the most advanced single-photodetector imaging system (such as Fourier and Hadamard single-pixel imaging) can capture a scene using programmed structured lights and a single photodetector (PD) without spatial resolution. Compared with megapixel array PDs, a single PD can more easily offer enhanced photodetection performance (such as higher responsivity, detectivity, and response speed) and hereby provides more opportunities for enhancements of imaging system . Such enhancements can significantly improve the imaging quality underwater with weak-light intensities due to scattering or absorption losses.…”

“…Compared with megapixel array PDs, a single PD can more easily offer enhanced photodetection performance (such as higher responsivity, detectivity, and response speed) and hereby provides more opportunities for enhancements of imaging system. 16 Such enhancements can significantly improve the imaging quality underwater with weaklight intensities due to scattering or absorption losses.…”

Advances in Photoelectric Detection Units for Imaging Based on Perovskite Materials

“…Mai's group established a set of single‐PDUs Fourier spectral imaging algorithm, which can realize 256 × 256 color imaging with high resolution and contrast ( Figure a). [ 90 ] The single‐PDUs can recognize color images to meet the requirements of commercial imaging, especially the image quality was better than Si‐PDUs in weak light. Further improvement of imaging performance can be achieved by reducing the current fluctuation range.…”

“…, d) imaging with high scattering medium (frosted glass), e) imaging in smoke and non-line-of-sight imaging; Reproduced with permission. [90] Copyright 2021, John Wiley and Sons. f) Imaging application of Cs 3 Bi 2 I 9 perovskite PDUs.…”

“…a) Imaging experimental setup of perovskite‐based single‐PDUs, results of 256 × 256 CsBi 3 I 10 PDUs pixels imaging: b) Low pass filtering image and spatial spectrum when cutoff frequency decreases (top‐down), c) reconstructed image with inverse Fourier transform when measurement number increases (bottom‐up), d) imaging with high scattering medium (frosted glass), e) imaging in smoke and non‐line‐of‐sight imaging; Reproduced with permission. [ 90 ] Copyright 2021, John Wiley and Sons. f) Imaging application of Cs 3 Bi 2 I 9 perovskite PDUs.…”