Pseudohalide‐Exchanged Quantum Dot Solids Achieve Record Quantum Efficiency in Infrared Photovoltaics
- 10 May 2017
- journal article
- research article
- Published by Wiley in Advanced Materials
- Vol. 29 (27)
- https://doi.org/10.1002/adma.201700749
Abstract
Application of pseudohalogens in colloidal quantum dot (CQD) solar‐cell active layers increases the solar‐cell performance by reducing the trap densities and implementing thick CQD films. Pseudohalogens are polyatomic analogs of halogens, whose chemistry allows them to substitute halogen atoms by strong chemical interactions with the CQD surfaces. The pseudohalide thiocyanate anion is used to achieve a hybrid surface passivation. A fourfold reduced trap state density than in a control is observed by using a suite of field‐effect transistor studies. This translates directly into the thickest CQD active layer ever reported, enabled by enhanced transport lengths in this new class of materials, and leads to the highest external quantum efficiency, 80% at the excitonic peak, compared with previous reports of CQD solar cells.Funding Information
- Natural Sciences and Engineering Research Council of Canada
- Nederlandse Organisatie voor Wetenschappelijk Onderzoek (680‐50‐1511)
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