Anomalous temperature dependence of photoluminescence lifetime in CsPbBr3 quantum dot-polymer film for optical thermometry.

Here, we report the temperature dependence of the photoluminescence (PL) lifetimes of didodecyl dimethylammonium bromide (DDAB)/tetraoctylammonium bromide (TOAB) capped CsPbBr3 QD-based films and the elucidation of their potential application to optical thermometry. Compared to the unstable oleic acid (OA)/oleylamine (OAm) capped CsPbBr3 QD film, DDAB/TOAB-CsPbBr3 QD film exhibits a reproducible temperature-dependent characteristic of PL lifetimes in the temperature range of 15–80 °C. The anomalous temperature-dependent feature of PL lifetimes, i.e., positively correlated with temperature, is observed from DDAB/TOAB-CsPbBr3 QD and DDAB/TOAB-CsPbBr3 QD-polymer films.