Admittance spectroscopy was used with a custom-built temperature stage to study deep level defects in four polycrystalline thin-film CdTe solar cells that had post-deposition back contact treatments with and without Cu and CdCl2. One hole trap signature with an activation energy of about 0.13eV was detected in all four cells and was attributed to a combination of VCd- and related complexes. A second hole trap with an activation energy of about 0.30eV and detected only in Cu-treated cells was attributed to CuCd-. A third hole trap with an activation energy of about 0.47eV was detected only in non-Cu-treated cells.

Cu and CdCl2 Influence on Defects Detected in CdTe Solar Cells with Admittance Spectroscopy. F.H.Seymour, V.Kaydanov, T.R.Ohno, D.Albin: Applied Physics Letters, 2005, 87[15], 153507 (3pp)