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Effective Use of UV‐Ozone Oxide in Silicon Solar Cell Applications
Author(s) -
Zin Ngwe,
Bakhshi Sara,
Gao Munan,
Ali Haider,
Kashkoush Ismail,
Schoenfeld Winston V.
Publication year - 2019
Publication title -
physica status solidi (rrl) – rapid research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.786
H-Index - 68
eISSN - 1862-6270
pISSN - 1862-6254
DOI - 10.1002/pssr.201800488
Subject(s) - ozone , passivation , oxide , materials science , wafer , analytical chemistry (journal) , layer (electronics) , optoelectronics , chemistry , nanotechnology , environmental chemistry , metallurgy , organic chemistry
It is long recognized that high‐quality surface cleaning is critical for an increased performance of solar cells and semiconductor devices. In this contribution, the effectiveness of UV‐ozone cleaning by comparing it against the industry standard RCAand UV‐assisted deionized water (DI‐O 3 ) techniques has been demonstrated. UV‐ozone cleaning results in an effective surface passivation quality that is comparable to both RCAand DI‐O 3 cleans, realizing a recombination current density ( J 0 ) of 7 fA cm −2 as compared to 5 and 8 fA cm −2 for RCAand DI‐O 3 cleans, respectively. Repeating the UV‐ozone clean on samples (i.e., growing of UV‐ozone oxide and stripping it in HF) more than twice results in a cleaning efficiency that is nearly identical to RCAclean. Based on a high resolution transmission electron microscopy analysis, the post‐annealed thickness of the UV‐ozone oxide layer was found to reduce in comparison to the pre‐annealed condition. This is likely due to oxygen diffusion from the UV‐ozone oxide layer into the overlaying AlO x layer. Additionally, it has been found that a reduction in UV‐ozone oxide deposition time to just 5 min still provides a comparable cleaning efficiency to the RCAclean, and also results in good passivation quality (5–8 fA cm −2 ) on both planar and textured samples.