Han, I.S., Kim, S.H., Kim, J.S. et al. (5 more authors) (2018) Electrical and optical characterizations of InAs/GaAs quantum dot solar cells. Applied Physics A: Materials Science and Processing, 124 (3). 245. ISSN 0947-8396
Abstract
© 2018, Springer-Verlag GmbH Germany, part of Springer Nature. The electrical and optical characterizations of InAs/GaAs quantum dot solar cells (QDSCs) were investigated by frequency dependent capacitance–voltage (C–V) measurements and photoreflectance (PR) spectroscopy. The C–V results confirmed that the frequency dependent junction capacitance (C j ) of QDSC is sensitive to the carrier exhaustion process through trapping and recapturing in the strain-induced defects and QD states caused by the interface strain between InAs and GaAs materials. As a result, at a low frequency (≤ 200 kHz), the C j of the QDSCs decreased with increasing InAs deposition thickness (θ), leading to the decrease in carrier concentration (N d ) of the n-GaAs absorber layer due to the carrier losses processes caused by the trapping and re-capturing in the defects and the relatively large QDs. At θ ≤ 2.0 ML, the p-n junction electric field strength (F pn ) of the QDSCs which was evaluated by PR spectra decreased with increasing excitation photon intensity (I ex ) due to the typical field screening effect in the SC structure. On the other hand, the F pn of QDSCs with θ ≥ 2.5 ML approached a constant value with a relatively high I ex , which suggests that the decrease in photo-generated carriers in the QDSC was caused by the re-capturing and trapping process.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © Springer-Verlag GmbH Germany, part of Springer Nature 2018 |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Engineering (Sheffield) > Department of Electronic and Electrical Engineering (Sheffield) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 01 Mar 2018 13:31 |
Last Modified: | 01 Mar 2018 13:31 |
Published Version: | https://doi.org/10.1007/s00339-018-1661-y |
Status: | Published |
Publisher: | Springer Verlag |
Refereed: | Yes |
Identification Number: | 10.1007/s00339-018-1661-y |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:128013 |