Luminescent emission of multi-junction InGaP/InGaAs/Ge PV cells under high intensity irradiation

Abstract Combined electroluminescence (EL) and photoluminescence (PL) measurements were conducted in order to investigate the presence of luminescent emission of InGaP/InGaAs/Ge at different operating conditions of the tandem. Luminescent emission from cell samples was observed at different sun concentrations, voltage biases and temperatures. A high intensity pulsed solar simulator was used to photoexcite the device which exhibited strong radiative recombination from both the top InGaP and middle InGaAs junctions. Luminescent emission from the device was investigated under a range of voltage biases and was clearly observed at the maximum power point voltage of the sample under test indicating its presence during typical operating conditions of the solar cells. Investigation of the emission was also performed at relatively high temperatures (up to 60 °C) in order to mimic the outdoor operating conditions of a solar cell device. Luminescence was detected at high temperatures indicating that significant radiative recombination is present at even higher temperatures. Outdoor measurements under actual solar spectrum demonstrated the presence of luminescent emission in agreement with indoor testing. The significant amount of radiative recombination at the band-gap edges of the top junctions observed in our measurements gives evidence that optical coupling to the lower ones may occur. Finally, excitation power dependent PL was performed using monochromatic laser sources in order to investigate the impact of externally induced photocurrents of different intensity upon the radiative signal of each junction.

[1]  J. Gordon,et al.  Temperature dynamics of multijunction concentrator solar cells up to ultra‐high irradiance , 2013 .

[2]  D. Law,et al.  40% efficient metamorphic GaInP∕GaInAs∕Ge multijunction solar cells , 2007 .

[3]  J. Nelson.  The physics of solar cells , 2003 .

[4]  John F. Geisz,et al.  Effect of Luminescent Coupling on the Optimal Design of Multijunction Solar Cells , 2014, IEEE Journal of Photovoltaics.

[5]  F. Dimroth,et al.  Effects of optical coupling in III-V multilayer systems , 2007 .

[6]  Jing-Jing Li,et al.  Luminescence coupling effects on multijunction solar cell external quantum efficiency measurement , 2013 .

[7]  Sarah Kurtz,et al.  Multijunction solar cells for conversion of concentrated sunlight to electricity. , 2010, Optics express.

[8]  G. Georghiou,et al.  Photoluminescence analysis of coupling effects: The impact of shunt resistance and temperature , 2014 .

[9]  Y. P. Varshni.  Temperature dependence of the energy gap in semiconductors , 1967 .

[10]  Greg P. Smestad,et al.  Optoelectronics of Solar Cells , 2002 .

[11]  Quantitative measurement and modeling of spontaneous emission efficiency of forward biased multi-junction solar cells , 2011, 2011 37th IEEE Photovoltaic Specialists Conference.

[12]  J. P. Connolly,et al.  Demonstration of Photon Coupling in Dual Multiple-Quantum-Well Solar Cells , 2012, IEEE Journal of Photovoltaics.

[13]  J. Harmand,et al.  Effect of temperature on the optical properties of GaAsSbN/GaAs single quantum wells grown by molecular-beam epitaxy , 2003 .

[14]  John F. Geisz,et al.  Analysis of Multijunction Solar Cell Current–Voltage Characteristics in the Presence of Luminescent Coupling , 2013, IEEE Journal of Photovoltaics.

[15]  George E. Georghiou,et al.  Electroluminescence and Photoluminescence Spectroscopy of Quantum Well Solar Cells , 2013 .

[16]  M. Green.  Solar Cells : Operating Principles, Technology and System Applications , 1981 .

[17]  Optical coupling from InGaAs subcell to InGaP subcell in InGaP/InGaAs/Ge multi-junction solar cells. , 2013, Optics express.

[18]  F. Dimroth,et al.  Temperature‐dependent electroluminescence and voltages of multi‐junction solar cells , 2014 .

[19]  K. Edmondson,et al.  Spectral response and energy output of concentrator multijunction solar cells , 2009 .

[20]  Uwe Rau,et al.  Reciprocity relation between photovoltaic quantum efficiency and electroluminescent emission of solar cells , 2007 .

[21]  George E. Georghiou,et al.  Voltage and light bias dependent quantum efficiency measurements of GaInP/GaInAs/Ge triple junction devices , 2013 .

[22]  Methods for analysis of two-functional, two-terminal photovoltaic devices , 1994, Proceedings of 1994 IEEE 1st World Conference on Photovoltaic Energy Conversion - WCPEC (A Joint Conference of PVSC, PVSEC and PSEC).