Enhanced optical properties of CsPbX3 (X = Cl, Br, and I) perovskite nanocrystal glasses through bismuth doping for light-emitting applications

Embedding all-inorganic CsPbX3 (X = Cl, Br, and I) perovskite nanocrystals (PNCs) into glass matrixes overcomes the instability of PNCs. However, there is still a significant need to enhance the photoluminescence properties of CsPbX3 PNC glasses for optoelectronic applications. Currently, there are few strategies to modulate the photoluminescence (PL) of CsPbX3 PNC glasses due to a lack of understanding regarding the precipitation and PL mechanism of PNCs in glass matrixes. In this work, effective strategies were proposed to enhance visible PL by using Bi ions as fluorescent probes and structural modifiers. The addition of Bi ions promoted the precipitation of CsPbX3 PNCs in glasses, and increased the photoluminescence quantum efficiency (PLQE) by 5-fold. Various characterisation studies demonstrated that Bi ions effectively compensated for structural defects and transferred energy to CsPbX3 PNCs, thereby suppressing non-radiative transitions. Furthermore, high-purity green- and red light emitting diodes (LEDs) were successfully fabricated by combining CsPbX3:Bi2O3 PNC glasses with blue LED chips. Clear fluorescence imaging was achieved using a miniaturised fluorescence detector with the green LED as an excitation source. This work provides a powerful strategy for designing highly efficient PNC glasses with potential applications in lighting, displays and bioimaging.