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Whittles TJ, Veal TD, Savory CN, Welch AW, de Souza Lucas FW, Gibbon JT, Birkett M, Potter RJ, Scanlon DO, Zakutayev A, Dhanak VR. Core Levels, Band Alignments, and Valence-Band States in CuSbS 2 for Solar Cell Applications. ACS Appl Mater Interfaces 2017; 9:41916-41926. [PMID: 29124940 DOI: 10.1021/acsami.7b14208] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The earth-abundant material CuSbS2 (CAS) has shown good optical properties as a photovoltaic solar absorber material, but has seen relatively poor solar cell performance. To investigate the reason for this anomaly, the core levels of the constituent elements, surface contaminants, ionization potential, and valence-band spectra are studied by X-ray photoemission spectroscopy. The ionization potential and electron affinity for this material (4.98 and 3.43 eV) are lower than those for other common absorbers, including CuInxGa(1-x)Se2 (CIGS). Experimentally corroborated density functional theory (DFT) calculations show that the valence band maximum is raised by the lone pair electrons from the antimony cations contributing additional states when compared with indium or gallium cations in CIGS. The resulting conduction band misalignment with CdS is a reason for the poor performance of cells incorporating a CAS/CdS heterojunction, supporting the idea that using a cell design analogous to CIGS is unhelpful. These findings underline the critical importance of considering the electronic structure when selecting cell architectures that optimize open-circuit voltages and cell efficiencies.
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Affiliation(s)
- Thomas J Whittles
- Stephenson Institute for Renewable Energy and Department of Physics, University of Liverpool , Liverpool L69 7ZF, U.K
| | - Tim D Veal
- Stephenson Institute for Renewable Energy and Department of Physics, University of Liverpool , Liverpool L69 7ZF, U.K
| | - Christopher N Savory
- Department of Chemistry, University College London , Christopher Ingold Building, London WC1H 0AJ, U.K
- Thomas Young Centre, University College London , Gower Street, London WC1E 6BT, U.K
| | - Adam W Welch
- Material Science Center, National Renewable Energy Laboratory , 15013 Denver W Parkway, Golden, Colorado 80401, United States
| | | | - James T Gibbon
- Stephenson Institute for Renewable Energy and Department of Physics, University of Liverpool , Liverpool L69 7ZF, U.K
| | - Max Birkett
- Stephenson Institute for Renewable Energy and Department of Physics, University of Liverpool , Liverpool L69 7ZF, U.K
| | - Richard J Potter
- Department of Mechanical, Materials and Aerospace Engineering, School of Engineering, University of Liverpool , Liverpool L69 3GH, U.K
| | - David O Scanlon
- Department of Chemistry, University College London , Christopher Ingold Building, London WC1H 0AJ, U.K
- Thomas Young Centre, University College London , Gower Street, London WC1E 6BT, U.K
- Diamond Light Source Ltd. , Diamond House, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, U.K
| | - Andriy Zakutayev
- Material Science Center, National Renewable Energy Laboratory , 15013 Denver W Parkway, Golden, Colorado 80401, United States
| | - Vinod R Dhanak
- Stephenson Institute for Renewable Energy and Department of Physics, University of Liverpool , Liverpool L69 7ZF, U.K
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McGovern RJ, Winston AE, Rouse RE, Welch AW. Reduction of Defoliation in Citrus Caused by Mycosphaerella citri with a Novel Biocompatible Fungicide. Plant Dis 2003; 87:134-138. [PMID: 30812917 DOI: 10.1094/pdis.2003.87.2.134] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
A novel, biocompatible fungicide, CD-2346, was evaluated for management of defoliation associated with greasy spot (Mycosphaerella citri Whiteside) in orange (Citrus sinensis (L.) Osbeck) and grapefruit (Citrus × paradisi Macfad.). This product contains potassium bicarbonate, potassium carbonate, urea, and a surfactant. CD-2346 (7.0 kg/ha) and a half-rate combination of CD-2346 + benomyl (0.55 kg/ha) were compared with a higher rate of benomyl (1.1 kg/ha) and commercial standards of oil (petroleum distillate FC-435-66 [70 to 93.5 liters/ha]) or oil (46.8 liters/ha) + copper sulfate (2.2 to 2.8 kg/ha). Fungicide efficacy was assessed using the area under the defoliation progress curve (AUDPC) and final defoliation in entire trees or final greasy spot severity in individual leaves. All fungicide treatments reduced the AUDPC, and all but benomyl reduced either final defoliation percentage or disease severity in individual leaves. CD-2346 and the reduced-rate combination of CD-2346 + benomyl were generally equal or superior to the full rate of benomyl in decreasing the AUDPC; CD-2346 + benomyl was equivalent to oil in reducing the AUDPC. Oil and CD-2346 treatments similarly reduced final defoliation, but oil + copper sulfate was superior to CD-2346 in reducing the AUDPC and final greasy spot defoliation or severity.
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Affiliation(s)
- R J McGovern
- University of Florida-IFAS, Plant Pathology Department, Gainesville 32611
| | - A E Winston
- Church & Dwight Co., Inc., Princeton, NJ 08540
| | - R E Rouse
- University of Florida-IFAS, Southwest Florida Research and Education Center, Immokalee, FL 34142
| | - A W Welch
- Welch Agricultural Services, Bradenton, FL 34206
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