Room-Temperature Doping of CsPbBr 3 Nanocrystals with Aluminum.

B-site doping is an emerging strategy for tuning the emission wavelength of cesium lead halide ABX 3 nanocrystals. We present a simple method for the postsynthetic doping of CsPbBr 3 nanocrystals with aluminum at room temperature by exposing them to a solution of AlBr 3 in dibromomethane. Despite the much smaller ionic radius of Al 3+ compared to that of Pb 2+ , nominal doping levels in a range from 8.1% to 24.3% were obtained when increasing the Al/Pb feed ratio from 1 to 4.5. Al 3+ introduction leads to a hypsochromic shift of the photoluminescence (PL) emission of the CsPbBr 3 nanocrystals. The PL peak position is highly stable over at least 6 months and tunable in a range of 510 to 480 nm by increasing the doping level. Structural analyses revealed a linear correlation between the PL energy and the lattice parameter with a slope of -1.96 eV/Å.