Lead Telluride Quantum Dot Solar Cells Displaying External Quantum Efficiencies Exceeding 120%
Top Cited Papers
Open Access
- 16 November 2015
- journal article
- research article
- Published by American Chemical Society (ACS) in Nano Letters
- Vol. 15 (12), 7987-7993
- https://doi.org/10.1021/acs.nanolett.5b03161
Abstract
Multiple exciton generation (MEG) in semiconducting quantum dots is a process that produces multiple charge-carrier pairs from a single excitation. MEG is a possible route to bypass the Shockley-Queisser limit in single-junction solar cells but it remains challenging to harvest charge-carrier pairs generated by MEG in working photovoltaic devices. Initial yields of additional carrier pairs may be reduced due to ultrafast intraband relaxation processes that compete with MEG at early times. Quantum dots of materials that display reduced carrier cooling rates (e.g., PbTe) are therefore promising candidates to increase the impact of MEG in photovoltaic devices. Here we demonstrate PbTe quantum dot-based solar cells, which produce extractable charge carrier pairs with an external quantum efficiency above 120%, and we estimate an internal quantum efficiency exceeding 150%. Resolving the charge carrier kinetics on the ultrafast time scale with pump–probe transient absorption and pump–push–photocurrent measuremen...Funding Information
- Studienstiftung des Deutschen Volkes
- European Research Council (259619)
- Conselho Nacional de Desenvolvimento Científico e Tecnológico (246050/2012-8)
- Gates Cambridge Trust
- Cambridge Commonwealth, European and International Trust
- Royal Society
- Cavendish Laboratory, University of Cambridge
- Engineering and Physical Sciences Research Council (EP/G037221/1, EP/G060738/1, EP/M005143/1)
This publication has 47 references indexed in Scilit:
- The promise and challenge of nanostructured solar cellsNature Nanotechnology, 2014
- Multiple Exciton Generation in Colloidal NanocrystalsNanomaterials, 2013
- Third Generation Photovoltaics based on Multiple Exciton Generation in Quantum Confined SemiconductorsAccounts of Chemical Research, 2012
- Multiple Exciton Generation in Semiconductor Quantum DotsThe Journal of Physical Chemistry Letters, 2011
- Comparing Multiple Exciton Generation in Quantum Dots To Impact Ionization in Bulk Semiconductors: Implications for Enhancement of Solar Energy ConversionNano Letters, 2010
- Evidence for Barrierless Auger Recombination in PbSe Nanocrystals: A Pressure-Dependent Study of Transient Optical AbsorptionPhysical Review Letters, 2008
- Multiple exciton generation in semiconductor quantum dotsChemical Physics Letters, 2008
- Highly Efficient Multiple Exciton Generation in Colloidal PbSe and PbS Quantum DotsNano Letters, 2005
- High Efficiency Carrier Multiplication in PbSe Nanocrystals: Implications for Solar Energy ConversionPhysical Review Letters, 2004
- Aspects of the Theory of Impact Ionization in Semiconductors (I)Physica Status Solidi (b), 1980