Title :
A Dry Heat-Induced Effect of Using Silver in CIGS Gridlines
Author :
Mann, J.R. ; Kempe, M. ; Repins, I. ; Duda, A. ; Glick, S. ; Kanevce, A.
Author_Institution :
Nat. Renewable Energy Lab., Golden, CO, USA
Abstract :
The ease with which screen-printed silver is deposited and its high conductivity make it an appealing choice for gridline material on CIGS-based photovoltaic devices. However, present results suggest silver diffusion into the device can cause severe reductions in efficiency after as little as 200 h at 85 °C. Dramatic reductions in fill factor, characterized by unusual inflections in the power quadrant of current-voltage curves, are observed for devices with silver gridlines but not for those with nickel or aluminum gridlines. The shape of the current-voltage curves demonstrate that the degradation mode is not simply due to changes in resistance but is consistent with the creation of a secondary barrier near the device junction.
Keywords :
copper compounds; diffusion; gallium compounds; indium compounds; photoconductivity; photoemission; silver; ternary semiconductors; Ag; CIGS gridlines; CIGS-based photovoltaic devices; Cu(InGa)Se2; conductivity; current-voltage curve shape; degradation mode; device junction; dry heat-induced effect; fill factor; gridline material; power quadrant; screen-printed silver; secondary barrier creation; silver diffusion; silver gridlines; temperature 85 degC; time 200 h; Degradation; Materials; Nickel; Photovoltaic systems; Resistance; Silver; Buffer; Cu(In,Ga)Se$_{2}$ (CIGS); diffusion; gridlines; photocurrent; silver;
Journal_Title :
Photovoltaics, IEEE Journal of
DOI :
10.1109/JPHOTOV.2012.2219852
