On the structure, synthesis, and characterization of ultrafast blue-emitting CsPbBr3 nanoplatelets

Abstract

Recent developments in medical imaging techniques, in particular, those in time-of-flight positron emission tomography put new challenges on scintillating material performance that cannot be fulfilled by conventional scintillators. Bright and ultrafast nanoparticles represent promising candidates to build up an advanced detection system needed. We synthesize colloidal CsPbBr3 nanoplatelets emitting blue light with fast sub-nanosecond decay. We also prepare a nanocomposite material by embedding the nanoplatelets in the polystyrene matrix. We show that blue emission is preserved provided the composite is not exposed to UV/vis light and/or elevated temperatures. Motivated by conflicting information from the literature about the room temperature structure of colloidal CsPbX3 (X = Cl, Br, I) particles, that results being orthorhombic, rather than cubic, we perform ab initio electronic structure calculations of bulk crystals with an orthorhombic structure. We calculate optical properties, as well as exciton diameters and binding energies and compare them to those previously obtained for cubic CsPbX3 crystals.

Transforming colloidal Cs4PbBr6 nanocrystals with poly(maleic anhydride-alt-1-octadecene) into stable CsPbBr3 perovskite emitters through intermediate heterostructures

“…The sub-ns PL decay of NCs in blends with PMAO, combined with a reasonable PLQY, should be of interest for applications in scintillators, where ultrafast and efficient emission is required for fast timing capability of imaging detectors. 61,62…”

On the Role of Cs4PbBr6 Phase in the Luminescence Performance of Bright CsPbBr3 Nanocrystals

“…This clearly indicates preferential orientation of nanocrystalline phase in this direction, suggesting the presence of nanoplatelets. As we have demonstrated, this type of synthesis is indeed capable of producing CsPbBr 3 nanoplatelets in the supernatant [ 50 ]. Nevertheless, Figure 1 still provides only a partial evidence of the CsPbBr 3 nanocrystals present in the centrifuged sample, as there are many CsPbBr 3 diffraction lines missing in the pattern.…”

Low Roll‐Off Perovskite Quantum Dot Light‐Emitting Diodes Achieved by Augmenting Hole Mobility

“…As for CsPbI 3 perovskite, the effective masses of electrons and holes are of considerable difference. [ 39 ] Therefore, β for electrons should be 0.24 Å −1 , which is much lower than that for holes. Such result that electron mobility is 1.3 times as high as that of S2 QD film is greatly in accordance with the non‐equivalent increase on the mobilities of different carriers.…”