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SiO y N x /SiN x stack: a promising surface passivation layer for high‐efficiency and potential‐induced degradation resistant mc‐silicon solar cells
Author(s) -
Zhou Chunlan,
Zhu Junjie,
Zhou Su,
Tang Yehua,
Foss Sean E.,
Haug Halvard,
Nordseth Ørnulf,
Marstein Erik S.,
Wang Wenjing
Publication year - 2017
Publication title -
progress in photovoltaics: research and applications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.286
H-Index - 131
eISSN - 1099-159X
pISSN - 1062-7995
DOI - 10.1002/pip.2803
Subject(s) - passivation , materials science , wafer , solar cell , stack (abstract data type) , silicon , degradation (telecommunications) , equivalent series resistance , layer (electronics) , coating , crystalline silicon , energy conversion efficiency , optoelectronics , analytical chemistry (journal) , nanotechnology , electronic engineering , chemistry , electrical engineering , voltage , computer science , engineering , programming language , chromatography
A thin SiO y N x film was inserted below a conventional SiN x antireflection coating used in c‐Si solar cells in order to improve the surface passivation and the solar cell's resistance to potential‐induced degradation (PID). The effect of varying the flow ratio of the N 2 O and SiH 4 precursors and the deposition temperature for the SiO y N x thin film upon material properties were systematically investigated. An excellent surface passivation was obtained on FZ p‐type polished silicon wafers, with the best results obtained with a SiO y N x film deposited at a very low temperature of 130 °C and with an optical refractive index of 1.8. In the SiO y N x /SiN x stack structure, a SiO y N x film with ~6 nm thickness is sufficient to provide excellent surface passivation with an effective surface recombination velocity S eff < 2 cm/s. Furthermore, we applied the optimized SiO y N x /SiN x stack on multicrystalline Si solar cells as a surface passivation and antireflection coating, resulting in a 0.5% absolute average conversion efficiency gain compared with that of reference cells with conventional SiN x coating. Moreover, the cells with the SiO y N x /SiN x stack layers show a significant increase in their resistance to PID. Nearly zero degradation in shunt resistance was obtained after 24 h in a PID test, while a single SiN x ‐coated silicon solar cell showed almost 50% degradation after 24 h. Copyright © 2016 John Wiley & Sons, Ltd.