Open AccessPoint defects, compositional fluctuations, and secondary phases in non-stoichiometric kesterites
Author(s) -
Susan Schorr,
Galina Gurieva,
Maxim Guc,
Mirjana Dimitrievska,
Alejandro PérezRodríguez,
Víctor IzquierdoRoca,
Claudia Schnohr,
Juran Kim,
William Jo,
J. M. Merino
Publication year - 2019
Publication title -
jphys energy
Language(s) - English
Resource type - Journals
ISSN - 2515-7655
DOI - 10.1088/2515-7655/ab4a25
Subject(s) - kesterite , stoichiometry , crystallographic defect , materials science , phase (matter) , ternary operation , melting point , solar cell , czts , chemical physics , layer (electronics) , crystallography , nanotechnology , chemistry , optoelectronics , composite material , organic chemistry , computer science , programming language
The efficiency of kesterite-based solar cells is limited by various non-ideal recombination paths, amongst others by a high density of defect states and by the presence of binary or ternary secondary phases within the absorber layer. Pronounced compositional variations and secondary phase segregation are indeed typical features of non-stoichiometric kesterite materials. Certainly kesterite-based thin film solar cells with an off-stoichiometric absorber layer composition, especially Cu-poor/Zn-rich, achieved the highest efficiencies, but deviations from the stoichiometric composition lead to the formation of intrinsic point defects (vacancies, anti-sites, and interstitials) in the kesterite-type material. In addition, a non-stoichiometric composition is usually associated with the formation of an undesirable side phase (secondary phases). Thus the correlation between off-stoichiometry and intrinsic point defects as well as the identification and quantification of secondary phases and compositional fluctuations in non-stoichiometric kesterite materials is of great importance for the understanding and rational design of solar cell devices. This paper summarizes the latest achievements in the investigation of identification and quantification of intrinsic point defects, compositional fluctuations, and secondary phases in non-stoichiometric kesterite-type materials.