Bandgap engineering of halide perovskite nanoribbons for high-performance photodetection

Bandgap engineering of semiconductor nanowires or nanoribbons (NRs) offers a promising material foundation for multifunctional integrated optoelectronic devices and circuits. Among these materials, all-inorganic halide perovskites have emerged as a leading candidate for next-generation photoelectronic applications due to their outstanding optoelectronic properties. In this work, we report the direct synthesis of high-quality bandgap gradient lead halide perovskite (CsPbCl_3−3xBr_3x and CsPbBr_3−3xI_3x (x = 0–1)) NRs using a magnetic-pulling source-moving chemical-vapor-deposition (CVD) method. Microstructural characterizations reveal that these as-grown NRs possess high-quality single crystalline structures with continuously tunable compositions. The photoluminescence emissions of these perovskite NRs can be finely tuned across the entire visible spectrum (417–702 nm). Furthermore, photodetectors based on these perovskite NRs demonstrate exceptional photoelectric performance, including a high I_ON/I_OFF ratio (10⁴), superior responsivity (37.5 A/W), and remarkable detectivity (2.81 × 10¹³ Jones). A spatially resolved imaging sensor based on these perovskite NRs is also demonstrated, indicating promising applications in photoelectronic imaging circuits. These bandgap-tunable perovskite NRs provide a versatile materials platform for future integrated devices in electronics and optoelectronics.