Effects of rapid thermal annealing as back contacts activation treatment on CdS/CdTe multi-contacted solar cells. (March 2021)

• Record Type: Journal Article
• Authors: Fernández-Domínguez, E.; Torres-Delgado, G.; Castanedo-Pérez, R.; Márquez-Marín, J.; Zelaya-Ángel, O.
• Is Part Of: Superlattices and microstructures. Volume 151(2021)
• Publication Date: 2021-03
• Subjects: CdS/CdTe solar Cells -- RTA -- Multiple back-contacts -- CuxTe -- Back-contact activation; Superlattices as materials -- Periodicals; Microstructure -- Periodicals; Semiconductors -- Periodicals; Superréseaux -- Périodiques; Microstructure (Physique) -- Périodiques; Semiconducteurs -- Périodiques; 621.38152
• DOI: 10.1016/j.spmi.2021.106832
• Languages: English
• ISSNs: 0749-6036

Abstract

Abstract: Cd2 SnO4 /CdS/CdTe/Cux Te/Au structure solar cells were made in samples of 20 × 20 mm 2 . Multiple metallic back-contacts were deposited on each sample by thermal evaporation. A series of rapid thermal annealing treatments (RTA) were performed on the cells, controlling work pressure (Pw ) and temperature (Ta ), to activate the interface of CdTe-back contact. Several combinations of pressure (746 mbar ≤ Pw ≤ 1112 mbar) and temperature (180 °C ≤ Ta ≤ 260 °C) were studied. The best results were obtained for the lowest Pw, increasing the average efficiency from 6.9% to 9.8% as Ta increased. All photovoltaic parameters (VOC, JSC, FF, RS, and RSh ) were enhanced with the RTA treatments along with the dispersion values. Once the thermal activation's optimal conditions were determined, the highest efficiency was 11.3% with an RTA single treatment. The improvement is attributed to the formation of Cu1·85 Te phase. It is shown that this kind of thermal treatment on Cux Te/Au back-contact of the cells can be employed to obtain higher area solar cells. Highlights: CuTe/Au back contacts activated by RTA reduce the time and temperature of treatment. Photovoltaic parameters and their dispersion studied by multiple back contact samples. RTA on CuxTe/Au back contacts enhance PV parameters and reduce their dispersion. The presence of the Cu1·85 Te phase (uncommon) after RTA on Cux Te/Au back contacts.