Analysis of chromatic aberration effects in triple-junction solar cells using advanced distributed models

Abstract

Abstract-The consideration of real operating conditions for the design and optimization of a multij unction solar cell receiverconcentrator assembly is indispensable. Such a requirement involves the need for suitable modeling and simulation tools in order to complement the experimental work and circumvent its wellknown burdens and restrictions. Three-dimensional distributed models have been demonstrated in the past to be a powerful choice for the analysis of distributed phenomena in single-and dual-junction solar cells, as well as for the design of strategies to minimize the solar cell losses when operating under high concentrations. In this paper, we present the application of these models for the analysis of triple-junction solar cells under real operating conditions. The impact of different chromatic aberration profiles on the short-circuit current of triple-junction solar cells is analyzed in detail using the developed distributed model. Current spreading conditions the impact of a given chromatic aberration profile on the solar cell I-V curve. The focus is put on determining the role of current spreading in the connection between photocurrent profile, subcell voltage and current, and semiconductor layers sheet resistance.

Impact of optically nonuniform luminescence coupling effect to the limiting cell conversion efficiency in InGaP/GaAs/Ge triple junction solar cell

“…As for the perimeter region, an ideality factor of 2 was assumed for the diode model per subcell representing the edge recombination. [14][15][16][17][18]22 In Fig. 1, this is labeled as J 02p;i .…”

“…Good agreement of the measurements with the simulation model results suggests that the nonuniformity of the LC effect is optically induced. Moreover, it is less likely caused by edge recombination, which is typically modeled using electrical circuits alone [14][15][16][17][18] (see Appendix A.1). We have found that the absolute conversion efficiency reduction of the limiting cell due to nonuniform LC current generation is 1.35% at maximum LC efficiency.…”

Understanding causes and effects of non-uniform light distributions on multi-junction solar cells: Procedures for estimating efficiency losses

“…These spatial and spectral nonuniformities can cause current mismatch between the subcells in the MJ solar cell decreasing the cell current. For the case of high differences between irradiance profiles in the different subcells, the current spreading that depends on the lateral resistances of the cells (layers which make up the connection between two subcells ) can be the dominant factor of efficiency losses in high concentration systems (5,(9)(10)(11).…”

Evaluation of the reliability of commercial concentrator triple-junction solar cells by means of accelerated life tests (ALT)

“…Current which has to be injected in darkness to emulate working conditions. For that simulations with our 3D distributed model for triple-junction solar cells have been carried out [5], [6]. The criterion followed has been that the absolute value of current density through the junctions in darkness does not surpass at any point of the solar cell the current density photo-generated in the active area at 820 X [4].…”