Abstract:

Metal halide perovskites, represented by CsPbBr₃, possess outstanding properties such as high photoluminescence quantum yield, narrow emission linewidth and wide color gamut, making them promising applications in the areas of photodetection, solar cells and displays, etc. High-quality patterning is crucial for high-resolution and integrated optoelectronic devices. In order to explore the influence of polyvinylpyrrolidone (PVP) concentration on the morphological, optical, and environmental stabilities of inkjet-printed CsPbBr₃ nano-arrays, a series of CsPbBr₃ patterns were inkjet printed on the flexible polyethylene terephthalate (PET) substrates, which were modified by PVP layer with varied concentrations (0, 50, 100, 150 mg/mL). When the PVP concentration was controlled at 50 mg/mL, the printed CsPbBr₃ patterns exhibited uniform crystalline morphology with the smallest average grain size of 92 nm, achieving the highest photoluminescence intensity and a prolonged fluorescence lifetime of 91.5 ns. It is attributed to effective defect passivation effect via coordination interactions between carbonyl groups (C=O) of PVP chains and Pb²⁺ ions of perovskite, suppressing the non-radiative recombination pathways. Stability evaluations were conducted under conditions of 30 ℃ and 65-75% relative humidity for 30 d, with PVP concentrations of 0, 50, 100, and 150 mg/mL, and the flexible luminescent patterns retained 16.20%, 73.44%, 66.57%, and 54.91% of their initial emission intensity, respectively. The significant enhancement in the environmental stabilities mainly originated from the space confinement and encapsulation effect of PVP matrix on the CsPbBr₃ particles. This work provides deeper insight into the optimization of flexible perovskite patterning, thereby advancing prospects for potential application in high-performance and integrated optoelectronic devices.

Key words: CsPbBr₃, polyvinylpyrrolidone, inkjet printing, polyethylene terephthalate