Abstract
Thermal processing of Cu(In1-xGax)Se2 thin-films grown as part of photovoltaic devices on soda-lime glass leads to the incorporation of Na impurity atoms in the Cu(In1-xGax)Se2. Na contamination increases the photovoltaic efficiency of Cu(In1-xGax)Se2-based devices. The purpose of this investigation is to develop a model for the chemistry of Na in Cu(In1-xGax)Se2 in an effort to understand how itimproves performance. An analysis of x-ray photoelectron spectroscopy data shows that the Na concentration is equivalent 0.1 at. % in the bulk of Cu(In1-xGax)Se2 thin films and that the Na is bound to Se. The authors propose a model invoking the replacement of column III elements by Na during the growth of Cu(In1-xGax)Se2 thin films. Na on In and Ga sites would act as acceptor states to enhancephotovoltaic device performance.
Original language | American English |
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Pages (from-to) | 3044-3049 |
Number of pages | 6 |
Journal | Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films |
Volume | 15 |
Issue number | 6 |
DOIs | |
State | Published - 1997 |
NREL Publication Number
- NREL/JA-530-22781