Ruddlesden–Popper‐Phase Hybrid Halide Perovskite/Small‐Molecule Organic Blend Memory Transistors
Murali Gedda, Emre Yengel, Hendrik Faber, Fabian Paulus, Joshua Kreß, Ming‐Chun Tang, Siyuan Zhang, Christina A. Hacker, Prashant Kumar, Dipti R. Naphade, Yana Vaynzof, George Volonakis, Feliciano Giustino, Thomas D. Anthopoulos
Abstract
Abstract Controlling the morphology of metal halide perovskite layers during processing is critical for the manufacturing of optoelectronics. Here, a strategy to control the microstructure of solution‐processed layered Ruddlesden–Popper‐phase perovskite films based on phenethylammonium lead bromide ((PEA) 2 PbBr 4 ) is reported. The method relies on the addition of the organic semiconductor 2,7‐dioctyl[1]benzothieno[3,2‐b]benzothiophene (C 8 ‐BTBT) into the perovskite formulation, where it facilitates the formation of large, near‐single‐crystalline‐quality platelet‐like (PEA) 2 PbBr 4 domains overlaid by a ≈5‐nm‐thin C 8 ‐BTBT layer. Transistors with (PEA) 2 PbBr 4 /C 8 ‐BTBT channels exhibit an unexpectedly large hysteresis window between forward and return bias sweeps. Material and device analysis combined with theoretical calculations suggest that the C 8 ‐BTBT‐rich phase acts as the hole‐transporting channel, while the quantum wells in (PEA) 2 PbBr 4 act as the charge storage element where carriers from the channel are injected, stored, or extracted via tunneling. When tested as a non‐volatile memory, the devices exhibit a record memory window (>180 V), a high erase/write channel current ratio (10 4 ), good data retention, and high endurance (>10 4 cycles). The results here highlight a new memory device concept for application in large‐area electronics, while the growth technique can potentially be exploited for the development of other optoelectronic devices including solar cells, photodetectors, and light‐emitting diodes.