Extremely reduced dielectric confinement in two-dimensional hybrid perovskites with large polar organics
- King Abdullah Univ. of Science and Technology (KAUST), Thuwai (Saudi Arabia). Computer, Electrical, and Mathematical Sciences and Engineering Division
- King Abdullah Univ. of Science and Technology (KAUST), Thuwai (Saudi Arabia). KAUST Solar Center, Physical Sciences and Engineering Division
- SLAC National Accelerator Lab., Menlo Park, CA (United States). Stanford Synchrotron Radiation Lightsource (SSRL)
- Univ. of California, Berkeley, CA (United States). Dept. of Electrical Engineering and Computer Sciences
- King Abdullah Univ. of Science and Technology (KAUST), Thuwai (Saudi Arabia). Core Lab.
Two dimensional inorganic–organic hybrid perovskites (2D perovskites) suffer from not only quantum confinement, but also dielectric confinement, hindering their application perspective in devices involving the conversion of an optical input into current. In this report, we theoretically predict that an extremely low exciton binding energy can be achieved in 2D perovskites by using high dielectric-constant organic components. We demonstrate that in (HOCH2CH2NH3)2PbI4, whose organic material has a high dielectric constant of 37, the dielectric confinement is largely reduced, and the exciton binding energy is 20-times smaller than that in conventional 2D perovskites. As a result, the photo-induced excitons can be thermally dissociated efficiently at room temperature, as clearly indicated from femtosecond transient absorption measurements. In addition, the mobility is largely improved due to the strong screening effect on charge impurities. Such low dielectric-confined 2D perovskites show excellent carrier extraction efficiency, and outstanding humidity resistance compared to conventional 2D perovskites.
- Research Organization:
- Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES). Materials Sciences & Engineering Division; King Abdullah University of Science and Technology (KAUST) Office of Sponsored Research
- Grant/Contract Number:
- AC02-05CH11231; OSR-2016-CRG5-3005; FCC/1/3079-08-01
- OSTI ID:
- 1638985
- Journal Information:
- Communications Physics, Vol. 1, Issue 1; ISSN 2399-3650
- Publisher:
- Springer NatureCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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