Multiband Photoresponding Field‐Effect Transistor Memory Using Conjugated Block Copolymers with Pendent Isoindigo Coils as a Polymer Electret

Abstract

In this study, the authors report a series of conjugated block copolymers, PF‐b‐Piso comprising poly[2,7‐(9,9‐dihexylfluorene)] (PF), and poly(pendent isoindigo) (Piso) for polymer electret in the photonic field‐effect transistor (FET) memory device. The optical properties, surface morphology, and molecular organization of these BCPs are investigated systematically. Accordingly, Piso with absorption in the Ultraviolet C range (UVC, 200–280 nm) possibly rendered the device with a multiband photoresponse, and a good memory performance is achieved by optimizing the polymer composition. Therefore, the memory device comprising PF‐b‐Piso could perform a high current contrast of 106 to 405 nm light and 105 to 254 nm light over 104 s. In addition, a current contrast of 104 and 102 is achieved in response to 650 and 530 nm light, and this phenomenon can be attributed to the charge transfer between channel and memory layers. The experimental results indicate that the block copolymer design not only conduces to forming a self‐assembled microphase separation to stabilize the trapped charge in the polymer electret, but also triggers multiband photoresponding of the photonic FET memory.

Synthesis of ABCBA-type miktoarm H-shaped copolymers with poly(3-hexylthiophene) segments and their application to intrinsically stretchable photonic transistor memory

“…To examine the device performance of the H-CP electret, we compare our system with the reported transistor memory based on block copolymers and summarize their device architectures, programming parameters, and device performances in Table S1 (ESI†). 14,49–52 Accordingly, our device showed dual photo-electrical operating capability. The molecular design of H-CP electret requires less illumination power and programming time, assuring H-CP as a competitive material for photomemory.…”

Electrical Double-Layer Transistors Comprising Block Copolymer Electrolytes for Low-Power-Consumption Photodetectors

“…Organic phototransistors have been referred to as exceptional optoelectronic devices owing to their light weight, low cost, compatibility with integrated circuits, and ability to detect light and amplify signals. − Various ideas have been incorporated into phototransistors to improve device performance or endow memory capability, including floating gates − and polymer electrets. − In phototransistors, the combination of light and the external gate voltage is applied to modulate the carrier concentration in the semiconducting channel. Therefore, the gate voltage and light can configure the channel conductivity, allowing for highly tunable device performance.…”

Discotic Liquid Crystals with Highly Ordered Columnar Hexagonal Structure for Ultraviolet Light-Sensitive Phototransistor Memory

“…Recently, diverse electret design has been developed to improve the performance of phototransistor memory, including floating gate, − photoactive polymer, − and organic molecule electrets. ,, Floating gate electrets consist of dispersed photogates and photoinactive insulated polymer matrix. Photoactive polymer electrets are divided into two categories (i) conjugated/insulating polymer blends − and (ii) conjugated/insulating block copolymers. − With regards to the floating gate design, the device performance is usually hampered by the dispersity of photogates in a floating gate electret. Photoactive polymer electret requires an elaborate design to address its poor affordability.…”