Abstract
The energy disorder that arises from colloidal quantum dot (CQD) polydispersity limits the open-circuit voltage (VOC) and efficiency of CQD photovoltaics. This energy broadening is significantly deteriorated today during CQD ligand exchange and film assembly. Here, a new solution-phase ligand exchange that, via judicious incorporation of reactivity-engineered additives, provides improved monodispersity in final CQD films is reported. It has been found that increasing the concentration of the less reactive species prevents CQD fusion and etching. As a result, CQD solar cells with a VOC of 0.7 V (vs 0.61 V for the control) for CQD films with exciton peak at 1.28 eV and a power conversion efficiency of 10.9% (vs 10.1% for the control) is achieved.
Original language | English |
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Article number | 1703627 |
Journal | Advanced Materials |
Volume | 29 |
Issue number | 43 |
DOIs | |
State | Published - Nov 20 2017 |
Externally published | Yes |
Keywords
- colloidal quantum dots
- open-circuit voltage
- photovoltaics
- polydispersity
- solution-phase ligand exchange