2014 coatings-54978-final.pdf (2.01 MB)
Fabrication of CdS/CdTe-based thin film solar cells using an electrochemical technique
journal contribution
posted on 2016-03-15, 11:36 authored by I.M. Dharmadasa, Paul A. Bingham, O.K. Echendu, H.I. Salim, T. Druffel, Ruvini Dharmadasa, G.U. Sumanasekera, R.R. Dharmasena, M.B. Dergacheva, K.A. Mit, K.A. Urazov, L. Bowen, Michael WallsMichael Walls, Ali AbbasAli AbbasThin film solar cells based on cadmium telluride (CdTe) are complex devices which have great potential for achieving high conversion efficiencies. Lack of understanding in materials issues and device physics slows down the rapid progress of these devices. This paper combines relevant results from the literature with new results from a research programme based on electro-plated CdS and CdTe. A wide range of analytical techniques was used to investigate the materials and device structures. It has been experimentally found that n-, i- and p-type CdTe can be grown easily by electroplating. These material layers consist of nano- and micro-rod type or columnar type grains, growing normal to the substrate. Stoichiometric materials exhibit the highest crystallinity and resistivity, and layers grown closer to these conditions show n - p or p - n conversion upon heat treatment. The general trend of CdCl2 treatment is to gradually change the CdTe material’s n-type electrical property towards i-type or p-type conduction. This work also identifies a rapid structural transition of CdTe layer at 385 ± 5 °C and a slow structural transition at higher temperatures when annealed or grown at high temperature. The second transition occurs after 430 °C and requires more work to understand this gradual transition. This work also identifies the existence of two different solar cell configurations for CdS/CdTe which creates a complex situation. Finally, the paper presents the way forward with next generation CdTe-based solar cells utilising low-cost materials in their columnar nature in graded bandgap structures. These devices could absorb UV, visible and IR radiation from the solar spectrum and combine impact ionisation and impurity photovoltaic (PV) effect as well as making use of IR photons from the surroundings when fully optimised.
Funding
Numerous researchers have contributed to this research programme over the years. In particular, the main author would like to acknowledge the contributions from Chris Blomfield, Stephen McGregor, John McChesney, Anura Samanthilake, Nandu Chaure, Gavin Tolan, Gaafar Muftah, Jayne Wellings, Dahiru Diso, Osama El-Sherif, Ajith Weerasinghe, Fijay Fauzi, Azlian Abdul-Manaf, Mohammed Madugu and Olajide Olusola. To enable this research, funding received from Sheffield Hallam University, EPSRC, British Council, Commonwealth Scholarship programme, DTI-UK and several Governments (Malaysian, Kurdistan, Libyan and Nigerian) are gratefully acknowledged.
History
School
- Mechanical, Electrical and Manufacturing Engineering
Research Unit
- Centre for Renewable Energy Systems Technology (CREST)
Published in
CoatingsVolume
4Issue
3Pages
380 - 415Citation
DHARMADASA, I.M. ... et al., 2014. Fabrication of CdS/CdTe-based thin film solar cells using an electrochemical technique. Coatings, 4 (3), pp. 380-415.Publisher
© MDPIVersion
- AM (Accepted Manuscript)
Publisher statement
This work is made available according to the conditions of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) licence. Full details of this licence are available at: https://creativecommons.org/licenses/by-nc-nd/4.0/Publication date
2014eISSN
2079-6412Publisher version
Language
- en
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