Gallium gradients in Cu(In,Ga)Se2 thin-film solar cells
Wolfram Witte, Daniel Abou-Ras, Karsten Albe, Gottfried H. Bauer, Frank Bertram, Christian Boit, Rudolf Brüggemann, Jürgen Christen, Jens Dietrich, Axel Eicke, Dimitrios Hariskos, Matthias Maiberg, Roland Mainz, Max Meessen, Mathias Müller, Oliver Neumann, Thomas Orgis, Stefan Paetel, Johan Pohl, Humberto Rodriguez-Alvarez, Roland Scheer, Hans-Werner Schock, Thomas Unold, Alfons Weber and Michael Powalla
Article first published online: 28 MAR 2014 | DOI: 10.1002/pip.2485
We present a comprehensive study on the formation, nature, and consequences of gallium gradients in Cu(In,Ga)Se2 (CIGS) solar cells deposited by the sequential and co-evaporation processes.
The formation of gallium gradients is analyzed in real time during a selenization process and gallium gradients of CIGS layers grown by co-evaporation are analyzed by means of mass spectrometry and served as input for simulations.
Depth-dependent lateral inhomogeneities in CIGS were investigated by luminescence measurements, and migration barriers were calculated using density functional theory.