Green solvent assisted preparation of one-dimensional CsPbBr3 nanocrystals with a controllable morphology for cyan-emitting applications

Abstract

The ligand assisted reprecipitation (LARP) approach is a convenient method for synthesizing CsPbX₃ NCs at room temperature. However, several remaining challenges limit its further development, such as the utilization of toxic solvents and fast crystallization brings colloidal uncontrollable synthesis issues. In this work we apply the principles of green chemistry to the LARP technique for synthesizing CsPbBr₃ NCs under ambient conditions in a controllable way. Through the variation of non-toxic ester solvents with different polarity and reaction time, we demonstrate the size tunability of one-dimensional (1D) CsPbBr₃ nanocrystals synthesized in a green solvent system. Due to the strong quantum confinement effect, the obtained CsPbBr₃ NCs exhibited a wide photoluminescence emission (471–508 nm) and high quantum yield up to 78%. Interpretations on the related growth mechanism of CsPbBr₃ nanocrystals in a polarity-mediated solution are suggested for exploring effective strategies towards high-quality inorganic perovskite nanocrystals with definite morphologies. Finally, to explore the potential applications of CsPbBr₃ in white light-emitting diodes (WLEDs), cyan emission of CsPbBr₃ NCs (480 nm) is combined with blue, green, and red emissions from commercial powders to achieve white light with excellent vision performance. The device displays a super high color rendering index of 96.5.