Please use this identifier to cite or link to this item: http://hdl.handle.net/2445/172005
Title: Study and optimization of alternative MBE‐deposited metallic precursors for highly efficient kesterite CZTSe:Ge solar cells
Author: Giraldo, Sergio
Kim, Shinho
Andrade‐Arvizu, Jacob Antonio
Alcobé i Ollé, Xavier
Malerba, Claudia
Valentini, Matteo
Tampo, Hitoshi
Shibata, Hajime
Izquierdo‐Roca, Victor
Pérez Rodríguez, Alejandro
Saucedo, Edgardo
Keywords: Cèl·lules solars
Evaporació
Seleni
Solar cells
Evaporation
Selenium
Issue Date: 19-Jun-2019
Publisher: John Wiley & Sons
Abstract: Nowadays, most of the best efficiencies of Cu2ZnSn(S,Se)4 (CZTSSe) solar cells are obtained from absorber layers fabricated using sequential processes, including the deposition of metallic stack precursors, typically by sputtering, and followed by reactive annealing under chalcogen atmosphere. The sputtering technique is widely known for the easy growth of metallic layers, although the deposition rates, growth morphology and nucleation, or the roughness can sometimes be an issue leading to inhomogeneities in the final layers. Nevertheless, MBE (molecular beam epitaxy) technique could have some advantages to obtain high‐quality metallic layers, with accurate control of the growth due to ultra‐high vacuum conditions and high purity. In this work, we study the use of advanced MBE systems to grow metallic stack precursors, alternatively to sputtering or thermal evaporation techniques, to obtain high‐quality CZTSe:Ge absorbers. Due to differences in the nature of each type of precursor, thermal annealing optimizations are presented by modifying some critical selenization parameters, such as the temperature or the selenium amount in order to obtain well‐crystallized absorbers. Detailed morphological, compositional, and structural characterizations show relevant features of each precursor, mainly related to the formation of MoSe2 at the back interface, and Se and Sn composition after selenization in different conditions. Regarding the solar cell devices, main efficiency limitations come from VOC and FF, which could be tentatively related to a noncontrolled selenization; different precursor reactivity, porosity, or composition; and different alkali diffusion during the reactive annealing. Finally, in the first optimization, a 9.2% efficiency device has been achieved with promising perspectives for future improvements.
Note: Reproducció del document publicat a: https://doi.org/10.1002/pip.3147
It is part of: Progress in Photovoltaics, 2019, vol. 27, num. 9, p. 779-788
URI: http://hdl.handle.net/2445/172005
Related resource: https://doi.org/10.1002/pip.3147
ISSN: 1062-7995
Appears in Collections:Articles publicats en revistes (Enginyeria Electrònica i Biomèdica)

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