Effect of annealing temperature on the properties of CsPbBr ₃ nanocrystal films via inkjet printing and its application in colour conversion layers

Inkjet printing has emerged as a sustainable and scalable approach for fabricating electronic and optoelectronic devices, offering precise material deposition with minimal waste. Among solution-processable materials, metal halide perovskites, particularly CsPbBr₃, have gained significant attention due to their exceptional optoelectronic properties, including high photoluminescence quantum yield, tuneable bandgap, and efficient charge transport. However, optimizing the inkjet-printing process remains a challenge, particularly post printing annealing since CsPbBr₃ nanocrystals are sensitive to environmental conditions. In this study, we systematically investigate the effect of annealing temperature on the structural, morphological, and photoluminescence properties of inkjet-printed CsPbBr₃ films. Our results reveal that thermal treatment plays a pivotal role in controlling grain size, crystallinity, defect density, and overall optoelectronic behaviour. Notably, a remarkable 70-fold enhancement in photoluminescence emission was observed, alongside a crystal structure morphology evolution from 3D to 0D and 2D structures through simple annealing offering transformative potential for optoelectronic applications. By elucidating the interplay between annealing conditions and film characteristics, this work provides key insights for optimizing inkjet-printed perovskite films, driving advancements in next-generation, sustainable, and high-performance printed electronics. The application of the printed films was successfully demonstrated as efficient colour conversion layers for optoelectronic devices.