Novel Application of Phosphorescent Material for Non‐Volatile Flash Photomemory and Artificial Photonic Synapse

Abstract

Phosphorescent materials have received considerable attention in organic solar cells (OSCs) due to their long emission lifetime and inhibited geminate recombination. Motivated by its particular photophysical property, herein, the spatially addressable bis(2‐benzo[b]thiophen‐2‐ylpyridine)(acetylacetonate)iridium(III) (Ir(bt)2(acac))/polystyrene‐b‐poly(4‐vinylpyridine) (PS‐b‐P4VP) as a photoactive floating‐gate is first demonstrated to explore the application of phosphorescent material on the photo‐responsive characteristics of photomemory and artificial photonic synapse. By manipulating the interfacial area between Ir(bt)2(acac)/PS‐b‐P4VP and active channel by a solvent annealing process, an ON/OFF current ratio of 103 and a low programming time of 700 ms can be achieved. The current study addresses the exciton lifetime of photoactive material functions in photomemory and highlights the interfacial area between photoactive materials and charge‐carrier transporting materials in reducing photo‐programming time.

Unveiling the Delayed Fluorescence Effects of Triplet–Triplet Annihilation Upconversion on the Photoresponse of Transistor Memory

“…In addition, Wiyanto et al applied a floating gate dielectric comprising a phosphorescent material of bis­(2-benzo­[ b ]­thiophen-2-ylpyridine)­(acetylacetonate)­iridium­(III) [Ir­(bt) 2 (acac)] and a block copolymer matrix of polystyrene- block -poly­(4-vinylpyridine) (PS- block -P4VP). The device presented a moderate I on / I off (∼10 3 ) without applying a gate bias during the reading and programing . Therefore, many studies have promoted the performance of optoelectronic devices by utilizing the afterglow effect.…”

“…The device presented a moderate I on /I off (∼10 3 ) without applying a gate bias during the reading and programing. 44 Therefore, many studies have promoted the performance of optoelectronic devices by utilizing the afterglow effect. In comparison to this study, the TTA-UC mechanism can also significantly enhance the photoresponse and memory performance of the device, showing a high I on /I off (∼10 6 ) without the application of gate bias during the reading and programing processes; in addition, it also endows phototransistors with additional and exceptional memory capability by utilizing the TTA-UC mechanism, thereby underlining the potential for future optoelectronic applications.…”

Recent developments of block copolymers in nonvolatile memory and artificial synapses

“…99 Notably, BCP with self-assembled nanostructures can significantly promote the device performance and photoresponse of artificial synapses. BCPs are possible to combine disparate molecules into a single polymer, including all-conjugated, 100 conjugated/ insulating, 20,89,97,101 and insulating [102][103][104] BCPs. Therefore, BCPs can be applied as both electret and channel with charge-trapping capability.…”

Generation of Long‐Lived Excitons in Room‐Temperature Phosphorescence 2D Organic and Inorganic Hybrid Perovskites for Ultrafast and Low Power‐Consumption Nonvolatile Photomemory

“…Among which, nonvolatile flash photomemories provide both photosensitive function and recording characteristics which could be further simplify the PICs design. [1][2][3][4][5] Versatile photoactive materials have been executed in photomemory to enable the photo-induced charge transfer between floating gate and chargetransporting material. [1,2,[6][7][8] When considering that the mechanism of organic photovoltaics is similar to nonvolatile flash photomemories, sufficient exciton lifetime seem to be required condition for effective charge separation for high-performance optoelectronic devices.…”

“…[1,2,[6][7][8] When considering that the mechanism of organic photovoltaics is similar to nonvolatile flash photomemories, sufficient exciton lifetime seem to be required condition for effective charge separation for high-performance optoelectronic devices. [5,7] Phosphorescence is the long-life emission which involves the flip of electron spin state from singlet to triplet excited state through the intersystem crossing and then relaxes back to the ground state via radiative relaxation. Recently, room-temperature phosphorescence (RTP) has received considerable attention due to its important applications in anticounterfeiting technologies, photodynamic therapy, bioimaging, and light-emitting devices.…”