Coherent Phonon-Induced Modulation of Charge Transfer in 2D Hybrid Perovskites |
| |
Authors: | Dovletgeldi Seyitliyev Xixi Qin Manoj K. Jana Svenja M. Janke Xiaowei Zhong Wei You David B. Mitzi Volker Blum Kenan Gundogdu |
| |
Affiliation: | 1. Department of Physics and Organic and Carbon Electronics Laboratories (ORaCEL), North Carolina State University, Raleigh, NC, 27695 USA;2. University Program in Materials Science and Engineering, Duke University, Durham, NC, 27708 USA;3. Thomas Lord Department of Mechanical Engineering and Materials Science, Duke University, Durham, NC, 27708 USA;4. Department of Chemistry, University of North Carolina, Chapel Hill, NC, 27599 USA |
| |
Abstract: | Electron–phonon interactions play an essential role in charge transport and transfer processes in semiconductors. For most structures, tailoring electron–phonon interactions for specific functionality remains elusive. Here, it is shown that, in hybrid perovskites, coherent phonon modes can be used to manipulate charge transfer. In the 2D double perovskite, (AE2T)2AgBiI8 (AE2T: 5,5“-diylbis(amino-ethyl)-(2,2”-(2)thiophene)), the valence band maximum derived from the [Ag0.5Bi0.5I4]2– framework lies in close proximity to the AE2T-derived HOMO level, thereby forming a type-II heterostructure. During transient absorption spectroscopy, pulsed excitation creates sustained coherent phonon modes, which periodically modulate the associated electronic levels. Thus, the energy offset at the organic–inorganic interface also oscillates periodically, providing a unique opportunity for modulation of interfacial charge transfer. Density-functional theory corroborates the mechanism and identifies specific phonon modes as likely drivers of the coherent charge transfer. These observations are a striking example of how electron–phonon interactions can be used to manipulate fundamentally important charge and energy transfer processes in hybrid perovskites. |
| |
Keywords: | coherent phonons charge transfer hybrid perovskites density functional theory |
|
|