| AVS 54th International Symposium | |
| Thin Film | Tuesday Sessions |
| Session TF-TuP |
| Session: | Aspects of Thin Films Poster Session |
| Presenter: | D.N. Hebert, University of Illinois at Urbana-Champaign |
| Authors: | D.N. Hebert, University of Illinois at Urbana-Champaign A.J. Hall, University of Illinois at Urbana-Champaign A. Rockett, University of Illinois at Urbana-Champaign |
| Correspondent: | Click to Email |
Cu(In,Ga)Se2 (CIGS) and related materials yield the highest performance thin film solar cells and show excellent promise for very high efficiency multijunction devices if adequate single junction devices can be produced. However, intrinsic defect chemistry and the origin of band edge fluctuations are not understood and are likely responsible for limited device performance. Low-temperature, long-wavelength photoluminescence excitation (PLE) spectra of films with varying composition, growth temperature, substrate orientation and crystallinity are presented. Despite low excitation power, low-temperature, long-wavelength PLE measurements allow for the detection of luminescence by selective wavelength excitation and reveal sub-gap absorption bands. Position-dependent photoluminescence spectra acquired from epitaxial bicrystals and apertured photoluminescence spectra on device-grade polycrystals are also presented. Local area scanning tunneling microscopy band edge measurements on in situ cleaved and sputtered CIGS are used to interpret PL results.