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|Title:||Optical study on intrinsic exciton states in high-quality CH3NH3PbBr3 single crystals||Authors:||Thu Ha Do, T.
Granados del Águila, A.
|Issue Date:||2017||Source:||Thu Ha Do, T., Granados del Águila, A., Cui, C., Xing, J., Ning, Z., & Xiong, Q. (2017). Optical study on intrinsic exciton states in high-quality CH3NH3PbBr3 single crystals. Physical Review B, 96(7), 075308-. doi:10.1103/PhysRevB.96.075308||Series/Report no.:||Physical Review B||Abstract:||Organolead halide perovskites have emerged as potential building blocks for photovoltaic and optoelectronic devices. Yet the underlying fundamental physics is not well understood. There is lack of agreement on the electronic band structures and binding energies of coupled electron-hole pairs (excitons), which drive the photophysical processes. In this work, we conducted temperature-dependent reflectance and photoluminescence experiments on high-quality CH3NH3PbBr3 single crystals. Two direct optical transitions corresponding to intrinsic free-excitons are clearly resolved, showing excellent consistence between the low-temperature (T=10 K) reflectance and photoluminescence spectra. Remarkably, the excitons have different binding energies and behave oppositely with temperature, suggesting distinctive origins. Moreover, the asymmetric photoluminescence profile is counterintuitively dominated by the high-energy exciton that is explained by a long relaxation time between levels and by the favorable generation rate of electron-hole pairs at the high-energy band. Our study opens access to the intrinsic properties of CH3NH3PbBr3 and sheds light to reconcile the large range of binding energies reported on these emergent direct band-gap semiconductors.||URI:||https://hdl.handle.net/10356/80794
|ISSN:||2469-9950||DOI:||http://dx.doi.org/10.1103/PhysRevB.96.075308||Rights:||© 2017 American Physical Society (APS). This paper was published in Physical Review B and is made available as an electronic reprint (preprint) with permission of American Physical Society (APS). The published version is available at: [http://dx.doi.org/10.1103/PhysRevB.96.075308]. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law.||Fulltext Permission:||open||Fulltext Availability:||With Fulltext|
|Appears in Collections:||SPMS Journal Articles|
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