Observatorio de I+D+i UPM

Memorias de investigación
Communications at congresses:
Photoreflectance for quality control of CIGS thin film solar cells
Year:2012
Research Areas
  • Electric engineers, electronic and automatic (eil),
  • Materials for electric engineering and electronics,
  • Solar cells,
  • Technology of devices for engineering
Information
Abstract
Photoreflectance (PR) is the contactless form of the modulation spectroscopy techniques. PR setup consists of a tunable wavelength probe beam for measuring the reflectance at the surface of a semiconductor. A modulated pump beam, for which photon energy is above the sample band gap, overlaps the probe beam at the sample surface. The resulting PR spectrum is defined as the relative change of the probe reflection induced by the pump laser. Because of its derivative-like features, the PR spectrum is sharp and very sensitive to fundamental and higher optical transitions. In addition, PR is a non-destructive technique working at room temperature which is of high interest for in-line control of CIGS thin films. In this study, many efforts are provided for optimizing PR setup for electrodeposited CIGS measurements. Issues such as photoluminescence perturbation, high roughness and scattering behavior are addressed. Adequate photon energies for the pump source are also used to probe in the complete stack either the CdS buffer layer (447 nm laser) or the CIGS absorber (633 or 850 nm lasers) at several depths. Considering the low electric field regime, material parameters are extracted by employing the third derivative form of dielectric functions to fit data. Thus, it is shown that the line shape and the position of the optical transition are intrinsically linked to the band gap, alloy composition and solar cell efficiency.
International
Si
Congress
E-MRS 2012 Spring Meeting - Symposium Y: Advanced materials and characterization techniques for solar cells
960
Place
Estrasburgo, Francia
Reviewers
Si
ISBN/ISSN
000-00000-000-00
Start Date
14/05/2012
End Date
18/05/2012
From page
1
To page
2
Proc. E-MRS 2012 Spring Meeting - Symposium Y: Advanced materials and characterization techniques for solar cells
Participants
  • Autor: A. Moureau
  • Autor: David Fuertes Marron (UPM)
  • Autor: Irene Artacho Huertas (UPM)
  • Autor: L. Escoubas
  • Autor: J.J. Simon
  • Autor: C. Ruiz
  • Autor: V. Bermúdez
Research Group, Departaments and Institutes related
  • Creador: Grupo de Investigación: Silicio y Nuevos Conceptos para Células Solares
  • Centro o Instituto I+D+i: Instituto de Energía Solar
  • Departamento: Electrónica Física
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