Metal halide perovskite nanocrystals (NCs) have emerged as a new generation light emitting materials with narrow emissions and high photoluminescence quantum efficiencies (PLQEs). Various types of perovskite NCs, e.g. platelets, wires, and cubes, have been discovered to exhibit tunable emissions across the whole visible spectral region. Despite remarkable advances in the field of metal halide perovskite NCs over the last few years, many nanostructures in inorganic NCs have yet been realized in metal halide perovskites and producing highly efficient blue emitting perovskite NCs remains challenging and of great interest. Here we report for the first time the discovery of highly efficient blue emitting cesium lead bromide perovskite (CsPbBr3) NCs with hollow structures. By facile solution processing of cesium lead bromide perovskite precursor solution containing additional ethylenediammonium bromide and sodium bromide, in-situ formation of hollow CsPbBr3 NCs with controlled particle and pore sizes is realized. Synthetic control of hollow nanostructures with quantum confinement effects results in color tuning of CsPbBr3 NCs from green to blue with high PLQEs of up to 81 %.<br><div><br></div>
Abstract
Metal halide perovskites have recently been reported as excellent scintillators for X-ray detection. However, perovskite based scintillators are susceptible to moisture and oxygen atmosphere, such as the water solubility of CsPbBr3, and oxidation vulnerability of Sn2+, Cu+. The traditional metal halide scintillators (NaI: Tl, LaBr3, etc.) are also severely restricted by their high hygroscopicity. Here we report a new kind of lead free perovskite with excellent water and radiation stability, Rb2Sn1-x
Te
x
Cl6. The equivalent doping of Te could break the in-phase bonding interaction between neighboring octahedra in Rb2SnCl6, and thus decrease the electron and hole dimensionality. The optimized Te content of 5% resulted in high photoluminescence quantum yield of 92.4%, and low X-ray detection limit of 0.7 µGyair s−1. The photoluminescence and radioluminescence could be maintained without any loss when immersing in water or after 480,000 Gy radiations, outperforming previous perovskite and traditional metal halides scintillators.
Tailoring the electron and hole dimensionality to achieve efficient and stable metal halide perovskite scintillators