The effect of nanocrystal reaction time on Cu2ZnSn(S,Se)4 solar cells from nanocrystal inks

Autor: Andrew D. Collord, Hugh W. Hillhouse
Rok vydání: 2015
Předmět:
Zdroj: Solar Energy Materials and Solar Cells. 141:383-390
ISSN: 0927-0248
DOI: 10.1016/j.solmat.2015.05.010
Popis: The sintering of nanocrystals to form a bulk film is a promising route for the production of low cost Cu2ZnSn(S,Se)4 solar cells. However, very little is known about how the synthesis of the nanocrystals impacts the properties of the sintered film or the performance of the resulting photovoltaic device. Here, we present a study in which devices were made from NC inks with different reaction times. Variation in reaction time produces inks with different average size, composition, and compositional heterogeneity. Accounting for the influence of composition, we find that longer NC reaction times result in improved current collection, larger quasi-Fermi level splitting, lower defect concentrations, and higher power conversion efficiency in the selenized devices. The improvements correlate well with the breadth of the x-ray diffraction peaks, suggesting that the longer reaction times result in larger crystalline domain sizes, and that grain boundaries may act as non-radiative recombination sites. Further, the crystalline domain size in the sintered film is proportional to the mean NC size in the ink, suggesting that some interparticle sintering occurs but that the ultimate grain size in the film is dependent on the starting NC size.
Databáze: OpenAIRE