Title:	Insights Into the Light Trapping Mechanisms in 100 NM-Thick Nanopatterned Gaas Solar Cells
Author(s):	D.N. Micha, M. Giteau, A. Cattoni, J.-F. Guillemoles, S. Collin
Keywords:	Gallium Arsenide Based Cells, Optical Properties, III-V Semiconductors, Modelling, Thin Film
Topic:	Evolving and Emerging Technologies: Tandems; Thin Film absorbers; III-V; New Materials and Concepts; Advanced Modelling
Subtopic:	III-V and Related Compound Semiconductors
Event:	8th World Conference on Photovoltaic Energy Conversion
Session:	2DO.9.4
Pages:	279 - 281
ISBN:	3-936338-86-8
Paper DOI:	10.4229/WCPEC-82022-2DO.9.4
Price:	0,00 EUR
Document(s):	paper

Abstract/Summary:

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By maximizing the interaction of sunlight with the absorber, light trapping allows for more than one order of magnitude reduction in the solar cell thickness with minor impact on performance. This possibility has been experimentally demonstrated for mature technologies, such as Si and GaAs ultrathin solar cells, with very high shortcircuit currents (JSC). In this work, we optimize the optical properties of a 100 nm-thick GaAs solar cell using a periodic subwavelength diffraction grating and demonstrate an optically equivalent JSC of 27.2 mA/cm2. Along with the calculations of the optical properties and a detailed analysis of the losses, we present a step-by-step evolution of the light trapping design from a simple back mirror to an advanced design combining a semiconductor diffraction grating, a spacer layer and a flat mirror. Finally, we go one step further in the optimization using OptiPV, an in-house developed software. It combines optical simulations with electrical simulations using SCAPS, through the calculation of the carrier generation rate in stacks that include photonic nanostructuration, allowing to consider practical aspects of the device operation.