TY - GEN
T1 - Influence of damp heat on the electrical, optical, and morphological properties of encapsulated CuInGaSe 2 devices
AU - Sundaramoorthy, R.
AU - Pern, F. J.
AU - Teeter, G.
AU - Li, Jian V.
AU - Young, M.
AU - Kuciauskas, D.
AU - Call, N.
AU - Yan, F.
AU - To, B.
AU - Johnston, S.
AU - Noufi, R.
AU - Gessert, T. A.
PY - 2011
Y1 - 2011
N2 - CuInGaSe 2 (CIGS) devices, encapsulated with different backsheets having different water vapor transmission rates (WVTR), were exposed to damp heat (DH) at 85°C and 85% relative humidity (RH) and characterized periodically to understand junction degradation induced by moisture ingress. Performance degradation of the devices was primarily driven by an increase in series resistance within first 50 h of exposure, resulting in a decrease in fill factor and, accompanied loss in carrier concentration and widening of depletion width. Surface analysis of the devices after 700-h DH exposure showed the formation of Zn(OH) 2 from hydrolysis of the Al-doped ZnO (AZO) window layer by the moisture, which was detrimental to the collection of minority carriers. Minority carrier lifetimes observed for the CIGS devices using time resolved photoluminescence (TRPL) remained relatively long after DH exposure. By etching the DH-exposed devices and re-fabricating with new component layers, the performance of reworked devices improved significantly, further indicating that DH-induced degradation of the AZO layer and/or the CdS buffer was the primary performance-degrading factor.
AB - CuInGaSe 2 (CIGS) devices, encapsulated with different backsheets having different water vapor transmission rates (WVTR), were exposed to damp heat (DH) at 85°C and 85% relative humidity (RH) and characterized periodically to understand junction degradation induced by moisture ingress. Performance degradation of the devices was primarily driven by an increase in series resistance within first 50 h of exposure, resulting in a decrease in fill factor and, accompanied loss in carrier concentration and widening of depletion width. Surface analysis of the devices after 700-h DH exposure showed the formation of Zn(OH) 2 from hydrolysis of the Al-doped ZnO (AZO) window layer by the moisture, which was detrimental to the collection of minority carriers. Minority carrier lifetimes observed for the CIGS devices using time resolved photoluminescence (TRPL) remained relatively long after DH exposure. By etching the DH-exposed devices and re-fabricating with new component layers, the performance of reworked devices improved significantly, further indicating that DH-induced degradation of the AZO layer and/or the CdS buffer was the primary performance-degrading factor.
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U2 - 10.1109/PVSC.2011.6186678
DO - 10.1109/PVSC.2011.6186678
M3 - Conference contribution
AN - SCOPUS:84861073909
SN - 9781424499656
T3 - Conference Record of the IEEE Photovoltaic Specialists Conference
SP - 3404
EP - 3409
BT - Program - 37th IEEE Photovoltaic Specialists Conference, PVSC 2011
T2 - 37th IEEE Photovoltaic Specialists Conference, PVSC 2011
Y2 - 19 June 2011 through 24 June 2011
ER -