Perovskite-Quantum Dots Interface: Deciphering its Ultrafast Charge Carrier Dynamics
Scholar | Other documents of the author: Galar, Pavel; Piatkowski, Piotr; Ngo, Thi Tuyen; Gutiérrez, Mario; Mora-Sero, Ivan; Douhal, Abderrazzak
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TitlePerovskite-Quantum Dots Interface: Deciphering its Ultrafast Charge Carrier Dynamics
Understanding electron and hole (e,h) transport at semiconductor interfaces is paramount to developing eﬃcientoptoelectronic devices. Halide perovskite/semiconductor quantum dots (QDs) have emerged as smart hybridsystems ... [+]
Understanding electron and hole (e,h) transport at semiconductor interfaces is paramount to developing eﬃcientoptoelectronic devices. Halide perovskite/semiconductor quantum dots (QDs) have emerged as smart hybridsystems with a huge potential for light emission and energy conversion. However, the dynamics of generated e-hpairs are not fully understood. Ultrafast UV–VIS transient absorption and THz spectroscopies have enabled us tounravel the processes of the e-h recombination within a hybrid ﬁlm of methylammonium lead triiodide (MAPbI3)interacting with diﬀerent amount of PbS/CdS core/shell QDs. To accurately analyze the complex behavior, weapplied a new model for e-h events in this hybrid material. The results obtained with sample having a highconcentration of QDs (7.3 mass percentage) indicate: (i) a large population (92%) of the photogenerated chargecarriers are aﬀected by QDs presence. The main part of these carriers (85% of the total) in perovskite domaindiﬀuse towards QDs, where they transfer to the interface (electrons) and QD´s valence bands (holes) with rateconstants of 1.2 × 1010s−1and 4.6 × 1010s−1, respectively. 7% of these aﬀected charged entities are excitonsin the perovskite domain in close vicinity of the interface, and show a recombination rate constant of 3.7 × 1010s−1.(ii) The carriers not aﬀected by QDs presence (8%) recombine through known perovskite deactivationchannels. Lowering the QDs mass percentage to 0.24 causes a decrease of electron and hole eﬀective transfer rateconstants, and disappearance of excitons. These results provide clues to improve the performance of perovskite/QD based devices [-]
Investigation projectMAT2014-57646-P ; MAT2016-76892-C3-1-R ; PEII-2014-003-P ; 724424 - No-LIMIT
Bibliographic citationGALAR, Pavel, et al. Perovskite-quantum dots interface: Deciphering its ultrafast charge carrier dynamics. Nano Energy, 2018, vol. 49, p. 471-480.
2211-2855/ © 2018 Elsevier Ltd. All rights reserved.
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