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Title: Ultrafast Exciton Dissociation at the 2D-WS 2 Monolayer/Perovskite Interface

Abstract

For an excitonic photovoltaic (PV) device to perform efficiently, photogenerated excitons in the charge donor need to be dissociated through charge transfer (CT) to the acceptor rapidly after their photogeneration and remain separated for a longer time to allow the collection of charges. To improve the efficiency of these steps, several combinations of materials have been examined. Due to their excellent optical properties, two-dimensional transition-metal dichalcogenides (2D-TMDs) have recently been explored. Another promising class of materials to platform efficient PVs is organic–inorganic perovskites. Here, we report on the ultrafast exciton dissociation through electron transfer from a 2D tungsten disulfide (WS 2) monolayer to a thin layer of methylammonium lead iodide (CH 3NH 3PbI 3) perovskites. Photoluminescence measurements showed that when the 2D-WS 2 monolayer was covered with perovskites, its emission completely quenched, suggesting that the CT process is highly efficient. Despite that pump–probe spectroscopy measurements were carried out with a ~45 fs temporal resolution, the CT dynamics were not captured. A comparison of the ultrafast dynamics of the two band-edge excitons of the charge donor (2D-WS 2) suggested that electron transfer is the dominant pathway of CT. Furthermore, these pump–probe measurements indicated that a small fraction of transferred electrons remainedmore » in the perovskites up to almost 2 ns. These findings may open a new horizon for understanding the dissociation of photogenerated excitons in 2D-TMDs through hybridization with another class of nanomaterials.« less

Authors:
 [1];  [1];  [2]; ORCiD logo [2]; ORCiD logo [2]; ORCiD logo [2]; ORCiD logo [1]
  1. California State Univ., Northridge, CA (United States)
  2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES)
OSTI Identifier:
1607233
Grant/Contract Number:  
AC05-00OR22725
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Journal of Physical Chemistry. C
Additional Journal Information:
Journal Volume: 122; Journal Issue: 50; Journal ID: ISSN 1932-7447
Publisher:
American Chemical Society
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; excitons; charge transfer; monolayers; hole transfer; perovskites

Citation Formats

Bauer, Joshua, Quintanar, Leo Scott, Wang, Kai, Puretzky, Alexander, Xiao, Kai, Geohegan, David, and Boulesbaa, Abdelaziz. Ultrafast Exciton Dissociation at the 2D-WS2 Monolayer/Perovskite Interface. United States: N. p., 2018. Web. doi:10.1021/acs.jpcc.8b08183.
Bauer, Joshua, Quintanar, Leo Scott, Wang, Kai, Puretzky, Alexander, Xiao, Kai, Geohegan, David, & Boulesbaa, Abdelaziz. Ultrafast Exciton Dissociation at the 2D-WS2 Monolayer/Perovskite Interface. United States. doi:10.1021/acs.jpcc.8b08183.
Bauer, Joshua, Quintanar, Leo Scott, Wang, Kai, Puretzky, Alexander, Xiao, Kai, Geohegan, David, and Boulesbaa, Abdelaziz. Thu . "Ultrafast Exciton Dissociation at the 2D-WS2 Monolayer/Perovskite Interface". United States. doi:10.1021/acs.jpcc.8b08183. https://www.osti.gov/servlets/purl/1607233.
@article{osti_1607233,
title = {Ultrafast Exciton Dissociation at the 2D-WS2 Monolayer/Perovskite Interface},
author = {Bauer, Joshua and Quintanar, Leo Scott and Wang, Kai and Puretzky, Alexander and Xiao, Kai and Geohegan, David and Boulesbaa, Abdelaziz},
abstractNote = {For an excitonic photovoltaic (PV) device to perform efficiently, photogenerated excitons in the charge donor need to be dissociated through charge transfer (CT) to the acceptor rapidly after their photogeneration and remain separated for a longer time to allow the collection of charges. To improve the efficiency of these steps, several combinations of materials have been examined. Due to their excellent optical properties, two-dimensional transition-metal dichalcogenides (2D-TMDs) have recently been explored. Another promising class of materials to platform efficient PVs is organic–inorganic perovskites. Here, we report on the ultrafast exciton dissociation through electron transfer from a 2D tungsten disulfide (WS2) monolayer to a thin layer of methylammonium lead iodide (CH3NH3PbI3) perovskites. Photoluminescence measurements showed that when the 2D-WS2 monolayer was covered with perovskites, its emission completely quenched, suggesting that the CT process is highly efficient. Despite that pump–probe spectroscopy measurements were carried out with a ~45 fs temporal resolution, the CT dynamics were not captured. A comparison of the ultrafast dynamics of the two band-edge excitons of the charge donor (2D-WS2) suggested that electron transfer is the dominant pathway of CT. Furthermore, these pump–probe measurements indicated that a small fraction of transferred electrons remained in the perovskites up to almost 2 ns. These findings may open a new horizon for understanding the dissociation of photogenerated excitons in 2D-TMDs through hybridization with another class of nanomaterials.},
doi = {10.1021/acs.jpcc.8b08183},
journal = {Journal of Physical Chemistry. C},
issn = {1932-7447},
number = 50,
volume = 122,
place = {United States},
year = {2018},
month = {11}
}

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Works referencing / citing this record:

Spintronics of Hybrid Organic–Inorganic Perovskites: Miraculous Basis of Integrated Optoelectronic Devices
journal, June 2019

  • Liao, Kun; Hu, Xiaoyong; Cheng, Yinke
  • Advanced Optical Materials, Vol. 7, Issue 15
  • DOI: 10.1002/adom.201900350