Correcting for interference effects in the photoluminescence of Cu(In, Ga)Se2 thin films. Issue 6 (21st February 2017)

• Record Type: Journal Article
• Authors: Wolter, Max Hilaire; Bissig, Benjamin; Reinhard, Patrick; Buecheler, Stephan; Jackson, Philip; Siebentritt, Susanne
• Is Part Of: Physica status solidi. Volume 14:Issue 6(2017)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2017-02-21
• Subjects: Cu(In, Ga)Se2 -- interference -- photoluminescence -- thin films; Solid state physics -- Congresses; Solid state physics -- Periodicals; Solid state physics; Conference proceedings; Periodicals; 530.41
• DOI: 10.1002/pssc.201600189
• Languages: English
• ISSNs: 1862-6351

Abstract

Abstract : Photoluminescence (PL) measurements are performed on high‐quality Cu(In, Ga)Se2 (CIGS) thin films with the intention of investigating their electronic structure. Due to the nature of the CIGS absorbers, notably their smooth surface and a graded band gap, the measured PL spectra are distorted by interference effects, limiting thus the information that one can gain. Here we show that, by varying the entrance angle of the laser light and the detection angle of the emitted PL, we are able to correct for interference effects. As a result, we receive interference‐free PL spectra that enable us to determine quantities such as band gap energies and quasi‐Fermi level splittings (QFLS). Furthermore, we show that it is possible to measure the QFLS even without correcting for interference effects and we compare the QFLS to the open circuit voltage for a particular sample.