Novel, stable, and lead-free CsCuBr₂ halides were synthesized and utilized as efficient light emitters.

The human visual system’s real-time focus-tunable imaging capability has inspired curved imaging system development. However, curved image sensors mimicking the human retina typically lack tunable curvature to match the curved Petzval surface throughout the focus-tunable range. Here, we propose a focus-tunable real-time curved imaging system based on a tunable-curvature perovskite curved image sensor. Using parylene C film for waterproofing and encapsulation, the ultrathin perovskite curved image sensor with the hierarchical mesh design is demonstrated, which conforms to spherical surfaces of different radii while maintaining mechanical stability during deformation. The image sensor exhibits low detection limit (10 nanowatts per square centimeter) and long-term stable dynamic photoresponse. Combining the image sensor with a tunable lens achieves clear images at different distances via simultaneously adjusting both sensor and lens radii. Furthermore, through integrating image sensor with a readout matrix and wireless data collection component, the real-time imaging system is demonstrated with real-time focus-tunable imaging capabilities.

A strategy to realize ZnO-based near-white-light electroluminescence (EL) was proposed by utilizing and regulating the intrinsic defect-related emissions of solution-processed ZnO nanocrystals (NCs). Prototype near-white light-emitting diodes (LEDs) based upon this strategy were demonstrated by using n-ZnO NCs/n-Si isotype heterojunctions. The emission color of the n-ZnO NCs/n-Si isotype heterojunction LEDs was tuned toward near white by using an Al-doped ZnO (AZO) spectral “scissor” which can tailor the green light more severely, rather than the blue or red light. Moreover, quantum size effect was clearly observed in both the photoluminescence (PL) and EL spectra via the redshift of the near-band-edge UV emission of the ZnO NCs. The strategy using AZO spectral “scissors” to regulate the V_O-related green emission of ZnO may present a promising pathway to realize ZnO-based white-light LEDs.