Characterization of the Manufacturing Processes to Grow Triple-Junction Solar Cells

By:N. A. Kalyuzhnyy [1], V. V. Evstropov[1], V. M. Lantratov[1], S. A. Mintairov[1],M. A. Mintairov[1], A. S. Gudovskikh[1],[2], A. Luque[1],[3], and V. M. Andreev[1]

[1] Ioffe Physical-Technical Institute of the Russian Academy of Sciences, Polytechnicheskaya Street 26, Saint Petersburg 194021, Russia

[2] Saint-Petersburg Academic University, Nanotechnology Research and Education Centre RAS, Hlopina Street 8/3, Staint Petersburg 194021, Russia

[3] Technical University of Madrid, Spain

International Journal of Photoenergy
Volume 2014 (2014), Article ID 836284, 10 pages
http://dx.doi.org/10.1155/2014/836284
Published 5 May 2014

Abstract

A number of important but little-investigated problems connected with III-V/Ge heterostructure in the GaInP/GaInAs/Ge multijunction solar cells grown by MOVPE are considered in the paper. The opportunity for successfully applying the combination of reflectance and reflectance anisotropy spectroscopy in situ methods for investigating III-V structure growth on a Ge substrate has been demonstrated. Photovoltaic properties of the III-V/Ge narrow-band subcell of the triple-junction solar cells have been investigated. It has been shown that there are excess currents in the Ge photovoltaic p-n junctions, and they have the tunneling or thermotunneling character. The values of the diode parameters for these current flow mechanisms have been determined. The potential barrier at the III-V/Ge interface was determined and the origin of this barrier formation during MOVPE heterogrowth was suggested.