Flexible Ultrathin Single-Crystalline Perovskite Photodetector.

Jing, Hao; Peng, Ruwen; Ma, Ren-Min; He, Jie; Zhou, Yi; Yang, Zhenqian; Li, Cheng-Yao; Liu, Yu; Guo, Xiaojiao; Zhu, Yingying; Wang, Di; Su, Jing; Sun, Cheng; Bao, Wenzhong; Wang, Mu

Flexible optoelectronic devices attract considerable attention due to their prominent role in creating novel wearable apparatus for bionics, robotics, health care, and so forth. Although bulk single-crystalline perovskite-based materials are well-recognized for the high photoelectric conversion efficiency than the polycrystalline ones, their stiff and brittle nature unfortunately prohibits their application for flexible devices. Here, we introduce ultrathin single-crystalline perovskite film as the active layer and demonstrate a high-performance flexible photodetector with prevailing bending reliability. With a much-reduced thickness of 20 nm, the photodetector made of this ultrathin film can achieve a significantly increased responsivity as 5600A/W, 2 orders of magnitude higher than that of recently reported flexible perovskite photodetectors. The demonstrated 0.2 MHz 3 dB bandwidth further paves the way for high-speed photodetection. Notably, all its optoelectronic characteristics resume after being bent over thousands of times. These results manifest the great potential of single-crystalline perovskite ultrathin films for developing wearable and flexible optoelectronic devices.