Nanographene‐Based Heterojunctions for High‐Performance Organic Phototransistor Memory Devices

Abstract

Organic phototransistors can enable many important applications such as nonvolatile memory, artificial synapses, and photodetectors in next‐generation optical communication and wearable electronics. However, it is still a challenge to achieve a big memory window (threshold voltage response ∆Vth) for phototransistors. Here, a nanographene‐based heterojunction phototransistor memory with large ∆Vth responses is reported. Exposure to low intensity light (25.7 µW cm−2) for 1 s yields a memory window of 35 V, and the threshold voltage shift is found to be larger than 140 V under continuous light illumination. The device exhibits both good photosensitivity (3.6 × 105) and memory properties including long retention time (>1.5 × 105 s), large hysteresis (45.35 V), and high endurance for voltage‐erasing and light‐programming. These findings demonstrate the high application potential of nanographenes in the field of optoelectronics. In addition, the working principle of these hybrid nanographene‐organic structured heterojunction phototransistor memory devices is described which provides new insight into the design of high‐performance organic phototransistor devices.

Monolayer Organic Crystals for Ultrahigh Performance Molecular Diodes

“…It closely approaches that of other DNTT‐based molecular films (C 10 ‐DNTT film for ≈ 2.6 eV). [ 33–35 ] Combing with UPS, the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital were estimated to be −4.95 and −2.33 eV for 1L, −4.93 and −2.35 eV for thin‐film C 6 ‐DNTT (Figure S10a, Supporting Information), respectively. The slight discrepancy in the energy level features may be due to the more inclined molecular packing in 1L, which has been observed in other organic small molecular systems.…”

A metastable small organic molecule for secure memory devices

“…[6][7][8][9][10][11][12][13][14][15][16] As part of the family of electronic devices, organic electrical memory devices have attracted enormous attention. [17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33] Recently, stimuli-responsive materials have been introduced into organic electrical memory devices realizing novel performance. For example, Song and co-workers developed photoinduced multilevel memory devices whose performance could be easily tuned and controlled from bistable switching behaviour to tristable switching behaviour through UV light.…”

Tuning of Interfacial Charge Transport in Organic Heterostructures via Aryl Electrografting for Efficient Gas Sensors

“…Organic heterostructures based on molecular semiconductors are becoming a research focus in the development of electronic devices owing to their high electrical transport being comparable to their inorganic counterparts. − Such materials have shown a highly correlated structure–property relationship, cost-effective synthesis, thin film processing by soft approaches, and high mechanical flexibility, , enabling their scalable production for extended area electronics. This is evidenced by the wide-scale use of the materials in different areas of organic electronics as an alternative to the inorganic semiconductors. − Gas sensing is another emerging application, in which modulation of electrical conductivity of organic heterostructure by chemical doping from gases is exploited to improve the metrological performances of sensors . Moreover, the presence of a hydrophobic and compact top layer in the heterostructure provides a kinetic barrier against the diffusion of molecular oxygen and water vapor, which otherwise negatively affect the operational stability of sensors, especially when the sensing layer is of n-type. , To develop organic heterostructures for sensing applications, metalloporphyrinoids such as metal phthalocyanine (MPc) and metal porphyrin (MP) are suitable candidates.…”