Atomic-Layer Deposition-Assisted Double-Side Interfacial Engineering for High-Performance Flexible and Stable CsPbBr Perovskite Photodetectors toward Visible Light Communication Applications.

Self-powered photodetectors (PDs) based on inorganic metal halide perovskites are regarded as promising alternatives for the next generation of photodetectors. However, uncontrollable film growth and sluggish charge extraction at interfaces directly limit the sensitivity and response speed of perovskite-based photodetectors. Herein, by assistance of an atomic layer deposition (ALD) technique, CsPbBr perovskite thin films with preferred orientation and enlarged grain size are obtained on predeposited interfacial modification layers. Thanks to improved film quality and double side interfacial engineering, the optimized CsPbBr (Al O /CsPbBr /TiO , ACT) perovskite PDs exhibit outstanding performance with ultralow dark current of 10 A, high detectivity of 1.88 × 10 Jones and broad linear dynamic range (LDR) of 172.7 dB. Significantly, excellent long-term environmental stability (ambient conditions >100 d) and flexibility stability (>3000 cycles) are also achieved. The remarkable performance is credited to the synergistic effects of high carrier conductivity and collection efficiency, which is assisted by ALD modification layers. Finally, the ACT PDs are successfully integrated into a visible light communication system as a light receiver on transmitting texts, showing a bit rate as high as 100 kbps. These results open the window of high performance all-inorganic halide perovskite photodetectors and extends to rational applications for optical communication.