Organic–inorganic hybrid perovskites have demonstrated tremendous potential for the next‐generation electronic and optoelectronic devices due to their remarkable carrier dynamics. Current studies are focusing on polycrystals, since controlled growth of device compatible single crystals is extremely challenging. Here, the first chemical epitaxial growth of single crystal CH3NH3PbBr3with controlled locations, morphologies, and orientations, using combined strategies of advanced microfabrication, homoepitaxy, and low temperature solution method is reported. The growth is found to follow a layer‐by‐layer model. A light emitting diode array, with each CH3NH3PbBr3crystal as a single pixel, with enhanced quantum efficiencies than its polycrystalline counterparts is demonstrated.
Organolead halide perovskites convert optical excitations to charge carriers with remarkable efficiency in optoelectronic devices. Previous research predominantly documents dynamics in perovskite thin films; however, extensive disorder in this platform may obscure the observed carrier dynamics. Here, carrier dynamics in perovskite single‐domain single crystals is examined by performing transient absorption spectroscopy in a transmissive geometry. Two distinct sets of carrier populations that coexist at the same radiation fluence, but display different decay dynamics, are observed: one dominated by second‐order recombination and the other by third‐order recombination. Based on ab initio simulations, this observation is found to be most consistent with the hypothesis that free carriers and localized carriers coexist due to polaron formation. The calculations suggest that polarons will form in both CH3NH3PbBr3and CH3NH3PbI3crystals, but that they are more pronounced in CH3NH3PbBr3. Single‐crystal CH3NH3PbBr3could represent the key to understanding the impact of polarons on the transport properties of perovskite optoelectronic devices.
more » « less- NSF-PAR ID:
- 10049295
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Optical Materials
- Volume:
- 6
- Issue:
- 5
- ISSN:
- 2195-1071
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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