Cyan-rich sunlight-like spectra from Mn2+-doped CsCd(Cl1−yBry)3 perovskites with dual tunable emissions and high stability

Abstract

A ubiquitous cyan gap in the white light emitting diode (WLED) emission spectrum, especially at 490–500 nm, has long hindered our quest for natural sunlight. In this paper, abundant cyan broadband emissions (peak at 496 nm) is first achieved in CsCd(Cl_1−yBr_y)₃ metal halide perovskites (MHPs) via a simple precipitation method to address this challenge. The Mn²⁺ ions are then doped in CsCd(Cl_1−yBr_y)₃ to supplement the yellow component. The resulting single-component white emitter CsCd_1−x (Cl_1−yBr_y)₃:xMn²⁺ phosphors possess an ultra-wide band emission from 350 nm to 750 nm, a pair of independent cyan and yellow emission peaks, and tunable color temperature (from 3000 K to 8000 K). The CsCd_0.65 (Cl_0.9Br_0.1)₃ : 0.35Mn²⁺ possesses excellent CIE 1931 color coordinates of (0.328, 0.348), a corresponding color temperature of 5690 K and a color rendering index of 90.96. In addition, this composites still has stable luminescence properties after 4 months of immersion in water. These results may stimulate the research on MHP-based single-component white emitter for the next generation of white light illumination.