High-performance organic broadband photomemory transistors exhibiting remarkable UV-NIR response

Abstract

The electrical and optical properties of organic semiconductors have improved rapidly in recent years, rendering them highly promising for various optoelectronic applications owing to low-cost and lightweight potential in combination with spectral tunability and long photocarrier lifetimes. Organic photomemory has emerged as an innovative application to achieve optical data storage. However, practical operation requires universal device design with broader spectral response in terms of related materials, interfaces and architecture, a task that remains a significant challenge. Herein, we present a universal strategy to fabricate organic broadband photomemories featuring remarkable UV-NIR response, thereby providing optical switching ability with a controllable memory window. To the best of our knowledge, this study demonstrates an excellent performance with the broadest response spectra and the highest photomemory efficiency of up to 593%. We systematically study the charge trapping mechanism and photoinduced injection enhancement by combining an energy level model with theoretical calculations, characterizing conceivable photogenerated minority carrier trapping and accumulation kinetics. Thus, it is anticipated that the proposed approach will be a starting point for further research, resulting in high-performance organic photomemory ideal for digital commutation between optical and electric signals.

Localized Surface Plasmon Resonance-Mediated Charge Trapping/Detrapping for Core–Shell Nanorod-Based Optical Memory Cells

“…To date, various possibilities have been employed to fabricate the OFET-based optical memory devices: (i) polymeric-gate electret layers, − (ii) upconversion nanoparticles and quantum dots, (iii) organic materials including small molecules, , organometallic complex, and carbon-based materials, (iv) photochromic materials, − and (v) two-dimensional materials such as MoS 2 . − However, these materials suffer from limitations in narrow light response range, and the synthetic ways of these materials are relatively complicated. It is highly desirable to utilize broad spectrum-responsive materials to construct an optical memory device through a facile fabrication method.…”

Recent Advances in Organic Phototransistors: Nonvolatile Memory, Artificial Synapses, and Photodetectors

“…Du et al reported a multimaterial phototransistor memory comprising lead phthalocyanine (PbPc, near infrared (NIR) red light), perylene dianhydride (PTCDA, green−blue light), and fullerene (C 60 , purple UV light). [ 119 ] The effectiveness of its heterojunction structure was reflected in its panchromatic photoresponse with a high memory window of 69 V under 405 nm light programming. However, the lack of an insulated medium for charge storage resulted in poor retention in the memory window of 15 V after 10 4 s. Qian et al reported a phototransistor memory with a vanadyl‐phthalocyanine (VOPc) channel on a p‐6P thin film.…”

High‐Performance Non‐Volatile Flash Photomemory via Highly Oriented Quasi‐2D Perovskite

“…Compared to electrically programmed memories, nonvolatile flash photomemory using photon as the firth terminal can store the light information to provide noncontact writing method that simplifies the design of integrated circuit. [1][2][3][4][5] Basically, the photomemory has the same architecture as the floating-gate memory whereas the photoactive and charge-trapping material as a substitute for conventional floating-gate to enable photo-programming capability. Photo-programming process possess phase separation due to the covalent links between two segments, leading to form a variety of ordered nanostructures such as lamellas, cylinders, and spheres by controlling the block ratio or the embedded small molecules.…”

“…Compared to electrically programmed memories, nonvolatile flash photomemory using photon as the firth terminal can store the light information to provide noncontact writing method that simplifies the design of integrated circuit. [ 1–5 ] Basically, the photomemory has the same architecture as the floating‐gate memory whereas the photoactive and charge‐trapping material as a substitute for conventional floating‐gate to enable photo‐programming capability. Photo‐programming process can be described as when the photon energy incident on the device, the generated electrons and holes from photo‐induced exciton will be separated between the charge‐trapping material and the charge‐transporting layer due to mismatched energy levels.…”