Deposition and optical properties of Mn2+-doped Cs3Cu2I5 thin films

The Cu-based metal halide Cs3Cu2I5is a promising material for optical devices due to its excellent optical properties such as blue emission with high photoluminescence quantum yield (PLQY), high ambient stability, and no toxicity. However, the control of the emission color by the halogen composition is restricted to the range between blue and green. To expand the emission color to the entire visible region, we aimed to control it by doping at the Cu-site. In this study, we selected Mn2+as a dopant for Cu sites and formed Mn2+-doped Cs3Cu2I5thin films using mist deposition. X-ray diffraction 2θ-ω scan revealed that polycrystalline thin films were formed at all Mn2+compositions. Energy dispersive X-ray spectroscopy illustrated that Mn2+was successfully doped into Cs3Cu2I5thin films. Photoluminescence (PL) spectra exhibited that Mn2+-doped Cs3Cu2I5has an additional peak with a wavelength of 550 nm, which is attributed to Mn2+.