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Evidence for a Light‐Induced Degradation Mechanism at Elevated Temperatures in Commercial N‐Type Silicon Heterojunction Solar Cells
Author(s) -
Wright Brendan,
Madumelu Chukwuka,
Soeriyadi Anastasia,
Wright Matthew,
Hallam Brett
Publication year - 2020
Publication title -
solar rrl
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.544
H-Index - 37
ISSN - 2367-198X
DOI - 10.1002/solr.202000214
Subject(s) - annealing (glass) , degradation (telecommunications) , solar cell , heterojunction , silicon , materials science , biophysics , chemistry , optoelectronics , composite material , biology , electronic engineering , engineering
The response of commercial n‐type silicon heterojunction (SHJ) solar cells to illuminated annealing at temperatures between 75 and 180 °C is reported on. Although a slight increase in efficiency of 0.1% absolute occurs at 75 °C under 1 sun illumination after 20 h, annealing at higher temperatures (85–180 °C) results in significant degradation in cell performance, and only occurs in the presence of illumination. At 160 °C, a loss in η up to 1% absolute is observed under 1 sun light soaking (LS) in as little as 2 min. Further illuminated annealing leads to a subsequent partial or full recovery of cell performance. At 160 °C, after an initial V OC degradation exceeding 10 mV within 3 min, a complete recovery is obtained after 60 min of illuminated annealing. The results indicate the potential presence of a light‐induced degradation mechanism in n‐type SHJ cells, suggesting care must be taken when using LS to improve efficiency. In addition, significant variability in the maximum extent of degradation indicates a high degree of cell‐to‐cell variation in expression of this degradation mechanism. The exact nature of the underlying defect mechanism(s) governing degradation and recovery dynamics remains uncertain and requires further studies.