Title :
Na diffusion in the Cu(In,Ga)Se/sub 2//Mo/glass system
Author :
Hanna, G. ; Schleussner, S. ; Bilger, G. ; Schock, H.W. ; Rau, Uwe ; Werner, J.H.
Author_Institution :
Inst. of Phys. Electron., Stuttgart Univ., Germany
Abstract :
This contribution investigates the kinetics of Na supply during growth of Cu(In,Ga)Se/sub 2/ thin films by means of secondary ion mass spectrometry. Na diffusion in Mo layers is fast and hence does not influence Na distribution between CIGS and Mo. Instead, Na-affinity of both layers determines Na distribution. Under normal CIGS growth conditions, Mo has a higher Na-affinity than CIGS whereas a decreased Se flux during growth and higher Ga contents increase Na-affinity in CIGS. Ionic exchange processes between H/sup +/ ions from the Mo layer and Na+ ions from glass are responsible for Na supply from glass during CIGS growth. The element Ga originating from CIGS layers can enhance Na extraction from glass probably by Ga/sup 3+//Na/sup +/ ion exchange.
Keywords :
chemical interdiffusion; copper compounds; gallium compounds; glass; indium compounds; ion exchange; molybdenum; secondary ion mass spectra; semiconductor thin films; sodium; ternary semiconductors; Cu(In,Ga)Se/sub 2//Mo/glass system; Cu(InGa)Se/sub 2/-Mo-Na/sub 2/O/sub 3/-CaO-SiO/sub 2/; Na distribution; Na-affinity; diffusion; ionic exchange processes; secondary ion mass spectrometry; thin film;
Conference_Titel :
Photovoltaic Energy Conversion, 2003. Proceedings of 3rd World Conference on
Conference_Location :
Osaka, Japan
Print_ISBN :
4-9901816-0-3
