Boosting the Photoluminescence of CsPbX < inf > 3 < /inf > (X = Cl, Br, I) Perovskite Nanocrystals Covering a Wide Wavelength Range by Postsynthetic Treatment with Tetrafluoroborate Salts

Abstract

A study was conducted to demonstrate the boosting of the photoluminescence (PL) of CsPbX3 (X = Cl, Br, I) perovskite nanocrystals covering a wide wavelength range by postsynthetic treatment with tetrafluoroborate salts. Purified nanocrystals (NCs) were dispersed in distilled, anhydrous toluene for further measurements. 2−4 mL of NC solution was stirred with solid NaBF4 or NH4BF4 for 30 min at room temperature and open atmosphere. The majority of the changes in the NC occur within the first 10 minutes and become unaffected after 30 minutes of the treatment. The outcome of the treatment was highly reproducible. The tetrafluoroborate salts were used directly after purchase in this method. Colloidal dispersion of the NCs remained unaffected after the treatment.