TY - JOUR
T1 - Engineering Interfacial Charge Transfer in CsPbBr3 Perovskite Nanocrystals by Heterovalent Doping
AU - Begum, Raihana
AU - Parida, Manas R.
AU - Abdelhady, Ahmed L.
AU - Banavoth, Murali
AU - AlYami, Noktan Mohammed
AU - Ahmed, Ghada H.
AU - Hedhili, Mohamed N.
AU - Bakr, Osman
AU - Mohammed, Omar F.
N1 - KAUST Repository Item: Exported on 2020-10-01
Acknowledgements: This work was supported by King Abdullah University of Science and Technology (KAUST). Also, part of this work was supported by a Saudi Arabia Basic Industries Corporation (SABIC) Grant RGC/3/2470-01.
PY - 2016/12/30
Y1 - 2016/12/30
N2 - Since compelling device efficiencies of perovskite solar cells have been achieved, investigative efforts have turned to understand other key challenges in these systems, such as engineering interfacial energy-level alignment and charge transfer (CT). However, these types of studies on perovskite thin-film devices are impeded by the morphological and compositional heterogeneity of the films and their ill-defined surfaces. Here, we use well-defined ligand-protected perovskite nanocrystals (NCs) as model systems to elucidate the role of heterovalent doping on charge-carrier dynamics and energy level alignment at the interface of perovskite NCs with molecular acceptors. More specifically, we develop an in situ doping approach for colloidal CsPbBr3 perovskite NCs with heterovalent Bi3+ ions by hot injection to precisely tune their band structure and excited-state dynamics. This synthetic method allowed us to map the impact of doping on CT from the NCs to different molecular acceptors. Using time-resolved spectroscopy with broadband capability, we clearly demonstrate that CT at the interface of NCs can be tuned and promoted by metal ion doping. We found that doping increases the energy difference between states of the molecular acceptor and the donor moieties, subsequently facilitating the interfacial CT process. This work highlights the key variable components not only for promoting interfacial CT in perovskites, but also for establishing a higher degree of precision and control over the surface and the interface of perovskite molecular acceptors.
AB - Since compelling device efficiencies of perovskite solar cells have been achieved, investigative efforts have turned to understand other key challenges in these systems, such as engineering interfacial energy-level alignment and charge transfer (CT). However, these types of studies on perovskite thin-film devices are impeded by the morphological and compositional heterogeneity of the films and their ill-defined surfaces. Here, we use well-defined ligand-protected perovskite nanocrystals (NCs) as model systems to elucidate the role of heterovalent doping on charge-carrier dynamics and energy level alignment at the interface of perovskite NCs with molecular acceptors. More specifically, we develop an in situ doping approach for colloidal CsPbBr3 perovskite NCs with heterovalent Bi3+ ions by hot injection to precisely tune their band structure and excited-state dynamics. This synthetic method allowed us to map the impact of doping on CT from the NCs to different molecular acceptors. Using time-resolved spectroscopy with broadband capability, we clearly demonstrate that CT at the interface of NCs can be tuned and promoted by metal ion doping. We found that doping increases the energy difference between states of the molecular acceptor and the donor moieties, subsequently facilitating the interfacial CT process. This work highlights the key variable components not only for promoting interfacial CT in perovskites, but also for establishing a higher degree of precision and control over the surface and the interface of perovskite molecular acceptors.
UR - http://hdl.handle.net/10754/622783
UR - http://pubs.acs.org/doi/full/10.1021/jacs.6b09575
UR - http://www.scopus.com/inward/record.url?scp=85014393432&partnerID=8YFLogxK
U2 - 10.1021/jacs.6b09575
DO - 10.1021/jacs.6b09575
M3 - Article
C2 - 27977176
SN - 0002-7863
VL - 139
SP - 731
EP - 737
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 2
ER -