Abstract
Multiple exciton generation (MEG) has great potential to improve the Shockley-Queisser (S-Q) efficiency limitation for colloidal quantum dot (CQD) solar cells. However, MEG has rarely been observed in CQD solar cells because of the loss of carriers through the transport mechanism between adjacent QDs. Herein, we demonstrate that excess charge carriers produced via MEG can be efficiently extracted using monolayer PbS QDs. The monolayer PbS QDs solar cells exhibit α=1 in the light intensity dependence of the short-circuit current density Jsc (Jsc∝Iα) and an internal quantum efficiency (IQE) value of 100 % at 2.95 eV because of their very short charge extraction path. In addition, the measured MEG threshold is 2.23 times the bandgap energy (Eg), which is the lowest value in PbS QD solar cells. We believe that this approach can provide a simple method to find suitable CQD materials and design interface engineering for MEG.
Original language | English |
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Pages (from-to) | 2657-2661 |
Number of pages | 5 |
Journal | ChemPhysChem |
Volume | 20 |
Issue number | 20 |
DOIs | |
Publication status | Published - 2019 Oct 16 |
Externally published | Yes |
Bibliographical note
Funding Information:This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIP) (2017R1 A2B3010927), the Global Frontier R&D Program on Center for Multiscale Energy System (2012 M3 A6 A7054855), the Future Materials Discovery Program (2016 M3D1 A1027664), and the Ministry of Education (2018R1D1 A1B07050694).
Publisher Copyright:
© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Keywords
- Langmuir–Blodgett
- colloid quantum dot solar cell
- fast charge extraction
- monolayer PbS
- multiple exciton generation
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Physical and Theoretical Chemistry