Flexible and Filter‐Free Color‐Imaging Sensors with Multicomponent Perovskites Deposited Using Enhanced Vapor Technology

Abstract

Halide perovskites are promising photoactive materials for filter‐free color‐imaging sensors owing to their outstanding optoelectronic properties, tunable bandgaps, and suitability for large‐scale fabrication. However, producing patterned perovskite films of sufficiently high quality for such applications poses a challenge for existing fabrication methods: using solution processes to prepare patterned perovskite films is complicated, while evaporation methods often result in perovskite photodetectors with limited performance. In this paper, the authors report the development of an improved evaporation method in which substrates are treated with a brominated (3‐aminopropyl) triethoxysilane self‐assembled monolayer to improve the properties of the patterned perovskite films. The resulting perovskite photodetectors exhibit significantly enhanced photosensitivity and long‐term stability (exceeding 100 days). Additionally, the polymer substrates facilitate device flexibility. Finally, perovskites comprising three different halide components, each with a different bandgap, are integrated into a device array using the developed evaporation technology, yielding sensors that enable the discrimination of red, green, and blue colors. Thus, the flexible photosensor arrays can generate colorful images closely resembling perceived patterns, demonstrating reliable color imaging. Therefore, this study successfully demonstrates filter‐free color‐imaging by integrating high‐performance patterned and multicomponent perovskite photodetectors, highlighting the potential of such detectors for advanced optoelectronic applications, including hyperspectral imaging.

Using Combinatorial Inkjet Printing for Synthesis and Deposition of Metal Halide Perovskites in Wavelength‐Selective Photodetectors

“…Once the photodetector is illuminated with the LED matching the absorption onset of the absorber material, a rise in responsivity by 2À3 orders of magnitude can be observed, comparable with previously reported values at comparable irradiance. [65][66][67] Let us consider possible applications of this observation. When operated individually, the responsivity of a single photodetector provides limited information (high/low responsivity).…”

“…Once the photodetector is illuminated with the LED matching the absorption onset of the absorber material, a rise in responsivity by 2−3 orders of magnitude can be observed, comparable with previously reported values at comparable irradiance. [ 65–67 ]…”

Flexible Perovskite and Organic Semiconductor Heterojunction Devices for Tunable Band-Selective Photodetection

“…17 −21 Taking advantage of the band gap tunability of perovskite materials, band-selective photodetection using perovskites with different band gaps has been reported. 22,23 increases the complexity of fabrication and integration. One strategy that can employ perovskites with different band gaps into a single device is thus further expected.…”

“…In recent decades, halide perovskites have emerged in photodetectors as a new class of optoelectronic materials with a high optical absorption coefficient, long carrier diffusion length, tunable optical band gap, and high carrier mobility. − Taking advantage of the band gap tunability of perovskite materials, band-selective photodetection using perovskites with different band gaps has been reported. , However, such efforts require combinations of several different devices, which increases the complexity of fabrication and integration. One strategy that can employ perovskites with different band gaps into a single device is thus further expected.…”

Ultrafast, Self-Powered, and Charge-Transport-Layer-Free Ultraviolet Photodetectors Based on Sequentially Vacuum-Evaporated Lead-Free Cs2AgBiBr6 Thin Films

“…Let alone, the spin-coating method falls far short of the industrial production required inherently. Vacuum evaporation has proved the superiority of high-quality and large-area perovskite films and has been applied to large-scale and high-performance photodetectors successfully. − In 2018, Liu et al constructed an evaporated Cs 2 AgBiBr 6 -based solar cell, obtaining a fair efficiency . However, high-performance photodetectors based on the evaporation-processed Cs 2 AgBiBr 6 thin film have not been exposed to public attention yet.…”