Biomaterial Database

Tunable Anisotropic Photon Emission from Self-Organized CsPbBr3 Perovskite Nanocrystals. 2017

Matthew J Jurow, and Thomas Lampe, and Erika Penzo, and Jun Kang, and Matthew A Koc, and Thomas Zechel, and Zachary Nett, and Michael Brady, and Lin-Wang Wang, and A Paul Alivisatos, and Stefano Cabrini, and Wolfgang Brütting, and Yi Liu

The Molecular Foundry, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.

We report controllable anisotropic light emission of photons originating from vertically aligned transition dipole moments in spun-cast films of CsPbBr3 nanocubes. By depositing films of nanocrystals on precoated substrates we can control the packing density and resultant radiation pattern of the emitted photons. We develop a technical framework to calculate the average orientation of light emitters, i.e., the angle between the transition dipole moment vector (TDM) and the substrate. This model is applicable to any emissive material with a known refractive index. Theoretical modeling indicates that oriented emission originates from an anisotropic alignment of the valence band and conduction band edge states on the ionic crystal lattice and demonstrates a general path to model the experimentally less accessible internal electric field of a nanosystem from the photoluminescent anisotropy. The uniquely accessible surface of the perovskite nanoparticles allows for perturbation of the normally isotropic emissive transition. The reported sensitive and tunable TDM orientation and control of emitted light will allow for applications of perovskite nanocrystals in a wide range of photonic technologies inaccessible to traditional light emitters.