TY - GEN
T1 - Characterization of Encapsulant Degradation in Accelerated UV Stressed Mini-Modules with UV-cut and UV-pass EVA
AU - Gopalakrishna, Hamsini
AU - Arularasu, Pooja
AU - Dolia, Kshitiz
AU - Sinha, Archana
AU - Tamizhmani, Govindasamy
N1 - Funding Information:
The funding support of Department of Energy, as a part of the PREDICTS 2 program (project DE-EE0007138) under SunShot initiative, is sincerely appreciated. We acknowledge SERIIUS for their collaborative help.
Publisher Copyright:
© 2019 IEEE.
PY - 2019/6
Y1 - 2019/6
N2 - Encapsulant browning and delamination are two common degradation modes in the crystalline silicon field exposed modules with ethyl vinyl acetate (EVA) as the encapsulant. Six mini-modules with two types of encapsulants: UV-cut (UVC) EVA and UV-pass (UVP) EVA, were exposed to an accelerated UV testing with total UV dosage of 800 kWh/m2 (between 300 nm - 400 nm) at different temperatures. The UVC mini-modules were maintained at 61°C, 66°C, and 73°C and the UVP mini-modules were maintained at 61°C, 67°C, and 70°C. UV fluorescence (UVF) imaging, cell-level Isc measurements, yellowness index measurements and reflectance measurements were performed intermittently to evaluate the cell performance. UVF images show an increased extent and intensity of browning in UVC mini-modules. The UVP mini-modules show delamination but no browning. The average Isc drop for three UVC and three UVP mini-modules were 2.0%, 3.7%, and 4.2%, and 3.1%, 4.4%, and 4.9%, respectively. Correspondingly, a yellowness index increase of 9.5, 12.4, and 17.2 for UVC and 0.28, 1.02, and 0.32 for UVP mini-modules was measured. The reflectance of UVC mini-modules showed an increase in the 500 nm - 700 nm wavelength range. The characterization results indicate that the EVA browning and delamination are the main degradation modes in UVC and UVP mini-modules, respectively.
AB - Encapsulant browning and delamination are two common degradation modes in the crystalline silicon field exposed modules with ethyl vinyl acetate (EVA) as the encapsulant. Six mini-modules with two types of encapsulants: UV-cut (UVC) EVA and UV-pass (UVP) EVA, were exposed to an accelerated UV testing with total UV dosage of 800 kWh/m2 (between 300 nm - 400 nm) at different temperatures. The UVC mini-modules were maintained at 61°C, 66°C, and 73°C and the UVP mini-modules were maintained at 61°C, 67°C, and 70°C. UV fluorescence (UVF) imaging, cell-level Isc measurements, yellowness index measurements and reflectance measurements were performed intermittently to evaluate the cell performance. UVF images show an increased extent and intensity of browning in UVC mini-modules. The UVP mini-modules show delamination but no browning. The average Isc drop for three UVC and three UVP mini-modules were 2.0%, 3.7%, and 4.2%, and 3.1%, 4.4%, and 4.9%, respectively. Correspondingly, a yellowness index increase of 9.5, 12.4, and 17.2 for UVC and 0.28, 1.02, and 0.32 for UVP mini-modules was measured. The reflectance of UVC mini-modules showed an increase in the 500 nm - 700 nm wavelength range. The characterization results indicate that the EVA browning and delamination are the main degradation modes in UVC and UVP mini-modules, respectively.
KW - Encapsulant browning
KW - UV cut
KW - UV pass
KW - delamination
KW - yellowness index
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U2 - 10.1109/PVSC40753.2019.8980897
DO - 10.1109/PVSC40753.2019.8980897
M3 - Conference contribution
AN - SCOPUS:85081637871
T3 - Conference Record of the IEEE Photovoltaic Specialists Conference
SP - 1961
EP - 1964
BT - 2019 IEEE 46th Photovoltaic Specialists Conference, PVSC 2019
PB - Institute of Electrical and Electronics Engineers Inc.
T2 - 46th IEEE Photovoltaic Specialists Conference, PVSC 2019
Y2 - 16 June 2019 through 21 June 2019
ER -