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Self‐powered photodetectors have paved the way for electronic applications in fields such as civilian communication, infrared mapping, and industrial automatic control. However, most self‐powered photodetectors have faced photoresponse‐speed and device‐scale bottlenecks. Herein, a novel, self‐powered detector with an ultrafast response speed based on a core–shell InN/In2S3 nanorod array is proposed. A wafer‐scale InN/In2S3 nanorod array with good homogeneity is synthesized on Si substrates via a simple two‐step method involving molecular beam epitaxy and chemical vapor deposition. The photodetector device exhibits excellent self‐powered properties and a high current on/off ratio of 5 × 103. Further analyses determined that the device have an excellent photovoltaic responsivity and detectivity of 140 mA·W−1 and 4.0 × 1010 Jones, respectively (0 V). Impressively, the device exhibits an ultrafast photoresponse with a rise/fall time of 22/32 µs. The self‐powered InN/In2S3 photodetector with an ultrafast response speed shows superior potential for electronic applications. The core–shell nanostructure hybrid heterojunction introduces a novel idea for wafer‐scale nano‐photodetectors. [ABSTRACT FROM AUTHOR]

Following the extensive researches of graphene, 2D layered semiconductors have attracted widespread attention for their intriguing physical properties. 2D α‐Ga2S3 as an important member of group IIIA–VIA semiconductors has outstanding optoelectronic properties. However, the controllable large‐size synthesis of ultrathin α‐Ga2S3 nanosheets still remains a huge challenge. In this paper, a large‐size ultrathin nanosheets of hexagonal Ga2S3 is prepared via an improved chemical vapor deposition method. High‐performance photodetectors based on the ultrathin Ga2S3 nanosheets is demonstrated. The device shows a high photosensitivity/detectivity (9.2 A W−1/1.4 × 1012 Jones) and a fast response time (rise/fall time of <4/3 ms), respectively. Strikingly, wearable flexible photodetectors based on Ga2S3 nanosheets are fabricated accordingly and demonstrate great response performance and stability. This work provides a new direction for 2D semiconductors to apply in next‐generation nanoscale smart optoelectronics. [ABSTRACT FROM AUTHOR]

Rapid and effective bone regeneration is still a major challenge in the clinical treatment of various bone diseases. Although recently developed electroactive materials have demonstrated high bone regeneration potential, the instability of the electrical stimulation and the unclear effects of the charge polarity on osteogenic differentiation hinder their clinical applications. In this work, GaN/AlGaN materials with well‐controlled polarity are used for the first time to induce endogenous electric stimulation and facilitate bone regeneration. By controlling the direction and magnitude of the piezoelectric and spontaneous polarization in the functional layer (GaN), charged GaN/AlGaN surfaces of opposite polarity, whose zeta potentials are within the range of the physiological potential, are obtained. Compared with N‐polarity GaN/AlGaN (with a positively charged surface), Ga‐polarity GaN/AlGaN (with a negatively charged surface) nanofilms show rapid and superior bone repair in vivo. In addition, the Ga‐polarity GaN/AlGaN hetero‐structures significantly promote the attachment, spreading, recruitment, and osteogenic differentiation of bone mesenchymal stem cells in vitro. Moreover, the bone morphogenetic protein‐6 (BMP6) expression profile in the early stages of osteogenic differentiation reveals that BMP6 may be an electrically sensitive osteogenic protein. This work sheds light on the application of III‐nitride materials in bone regeneration. [ABSTRACT FROM AUTHOR]