Flexible Thin Film and Bulk Switchable Relaxor Coexisting Most Optimal 473 nm Blue Light without Blue-Light Hazard/Visual Injury

Blue-light hazard in display will become a more serious problem because the wearable period is coming. Visual injury caused by the short wavelength is always the biggest challenge in red/green/blue ones. Therefore, the 470–475 nm is the most needed wavelength range to balance the visual injury and display effects. In addition, the combination of suitable wavelength, flexibility, and optic–electric coexistence has triggered a huge challenge in the wearable period to explore new blue-light materials. Under this epochal premise, lead-free blue light was introduced to form a dual photoelectric dielectric/blue-light switching flexible film/bulk crystal [Habf]2[ZnCl4]·2H2O (1) (Habf = p-ammonium benzene formamide), which will be a new breakthrough in photoelectric wearable devices. The coexistence of dielectric relaxation and high quantum yield in the most ideal emission wavelength facilitates the exploration of blue-light materials with low hazard, optical–electric response, and wearable characteristics in displays, multichannel controller, and new scenario requirements for optical–electric devices.