Size-controllable and stable organometallic halide perovskite quantum dots/polymer films

Organometallic halide perovskite quantum dots (OHP-QDs) have attracted a great deal of attention because of their high photoluminescence quantum yields (PLQYs, up to 90%) and narrow-band colors. However, precise control of the OHP-QDs' size is difficult and they are unstable under ambient conditions, which limits their usage in applications such as lasers and displays. Herein, we introduce a novel method to prepare size-controllable and stable OHP (methylammonium lead trihalide, MAPbX3, where X = Cl, Br, and I)-QDs/polymer films using polydimethylsiloxane (PDMS) as a template. The MAPbX3 QDs/PDMS films developed in this work are self-standing, flexible, transparent, and retain the photophysical properties of OHP-QDs for at least several months. Moreover, the uniform size of the OHP-QDs results in narrow photoluminescence (PL) emission (full-width-at-half-maximum, FWHM approximate to 20 nm) compared to that of QDs synthesized by a conventional method (approximate to 50 nm). The PL emission peak can be shifted by varying the size of the QDs and also by changing the halide component (Cl, Br, and I), covering a wide range of absorption wavelengths. Furthermore, the higher PL intensity of the larger QDs was confirmed by time-correlated single photon counting (TCSPC) experiments.