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.

Inorganic perovskite nanostructures have attracted considerable attention for their tunable band gaps and excellent optoelectronic properties. It is inevitable that phase segregation of halide perovskite usually occurs in mixed-halide perovskites under a focused laser illumination, which caused by photo-induced halide-ion segregation. Here, we reported an uniform perovskite alloy nanowires via a chemical vapor deposition (CVD) method. Microstructural characterization reveals that these perovskite nanowires have independent linear morphology with high-quality crystalline. Micro-photoluminescence (PL) spectra exhibit that these nanowire structures show a dual-wavelength emissions at 690 and 570 nm, respectively. Additionally, time-dependent PL intensity of the emission peak at 690 nm is increased by the decrease of the emission peak at 570 nm under a focused laser illumination, indicating the formation of phase segregation at the excited positions. Moreover, based on these as-grown halide perovskite CsPbBr_2.52I_0.48 nanowires, a reasonably optical switch is designed and constructed. This optical switch may have potential applications in timed blasting system and time-delay circuit in the future.