Abstract
We report a detailed study on APbX3 (A = formamidinium (FA+), Cs+ X = I-, Br-) perovskite quantum dots (PQDs) with combined A- and X-site alloying that exhibits both a wide bandgap and high open-circuit voltage (Voc) for the application of a potential top cell in tandem junction photovoltaic (PV) devices. The nanocrystal alloying affords control over the optical bandgap and is readily achieved by solution-phase cation and anion exchange between previously synthesized FAPbI3 and CsPbBr3 PQDs. Increasing only the Br- content of the PQDs widens the bandgap but results in shorter carrier lifetimes and associated Voc losses in devices. These deleterious effects can be mitigated by replacing Cs+ with FA+, resulting in wide-bandgap PQD absorbers with improved charge-carrier mobility and PVs with higher Voc.
Original language | American English |
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Pages (from-to) | 1954-1960 |
Number of pages | 7 |
Journal | ACS Energy Letters |
Volume | 4 |
Issue number | 8 |
DOIs | |
State | Published - 9 Aug 2019 |
Bibliographical note
Publisher Copyright:© 2019 American Chemical Society.
NREL Publication Number
- NREL/JA-5900-73572
Keywords
- alloys
- perovskite quantum dots
- photovoltaic devices