Title :
Experimental Evidence of Multiple Diffusion Mechanisms in Thin-Film Cu(In,Ga)Se2
Author :
Biderman, N.J. ; Novak, Steven W. ; Laursen, T. ; Sundaramoorthy, R. ; Haldar, Pradeep ; Lloyd, J.R.
Author_Institution :
Colleges of Nanoscale Sci. & Eng., State Univ. of New York (SUNY), Albany, NY, USA
Abstract :
Lattice and grain boundary diffusions of cadmium in copper indium gallium diselenide (Cu(In,Ga)Se2 or CIGS) thin films were investigated by annealing cadmium into samples of 700-nm CIGS thickness at temperatures between 250 and 300 °C. Diffusion profiles of cadmium were analyzed by dual-beam time-of-flight secondary ion mass spectroscopy (TOF-SIMS). In addition to fast cadmium grain boundary diffusion, experiments revealed cadmium diffusion profiles with two distinct lattice diffusion stages, which could be indicative of simultaneous vacancy and dissociative diffusion mechanisms.
Keywords :
annealing; cadmium; copper compounds; gallium compounds; grain boundary diffusion; indium compounds; secondary ion mass spectra; semiconductor thin films; ternary semiconductors; time of flight mass spectra; vacancies (crystal); Cd; Cu(InGa)Se2; TOF-SIMS; annealing; cadmium grain boundary diffusion; copper indium gallium diselenide thin films; dissociative diffusion mechanism; dual-beam time-of-flight secondary ion mass spectroscopy; lattice diffusion stages; multiple diffusion mechanisms; size 700 nm; temperature 250 degC to 300 degC; vacancy diffusion mechanism; Annealing; Cadmium; Cobalt; Copper; Grain boundaries; Sputtering; Surface treatment; Activation energy; cadmium; diffusion processes; grain boundaries; grain size; photovoltaic cells; thin films;
Journal_Title :
Photovoltaics, IEEE Journal of
DOI :
10.1109/JPHOTOV.2015.2459911
