Enhancing up-conversion luminescence in Yb/Er co-doped CsPbCl3 single crystals.

The search for and fabrication of materials for the near-infrared range of the spectrum, including telecommunication windows, is an extremely important task in modern technology. This work presents the results of studies on the photoluminescence of CsPbCl₃ single crystals with varying contents of ytterbium and erbium impurities, grown using the Bridgman method. The existence of electrically neutral Yb³⁺–V_Pb–Er³⁺ complexes within the crystal structure was confirmed. Resonant absorption of excitation radiation λ = 980 nm by Yb³⁺ ions reveals a three-step energy transfer channel from Yb³⁺ to Er³⁺ ions within a single complex. The estimated quantum yield of up-conversion luminescence at λ = 524 nm (0.02%) associated with erbium ions indicates the presence of electronic transitions to higher energy levels, with the possibility of subsequent emission within the third telecommunication window. [ABSTRACT FROM AUTHOR]