Design of metamorphic dual-junction InGaP/GaAs solar cell on Si with efficiency greater than 29% using finite element analysis

Abstract

Heterogeneous integration of multijunction III-V solar cells on Si is a promising solution for the widespread commercialization of III-V cells. However, the polar on non-polar epitaxy and 4% lattice-mismatch between GaAs and Si results in formation of defects and dislocations, which can significantly impede the minority carrier lifetime and hence the cell performance. We have investigated the impact of threading dislocation density on the performance of dual-junction (2J) n+/p InGaP/GaAs solar cells on Si. Using our calibrated model, the metamorphic 2J cell on Si was optimized by tailoring the 2J cell design on Si to achieve current-matching between the subcells at a realistic threading dislocation density of 10 6 cm -2 . We present a novel 2J InGaP/GaAs cell design on Si at a threading dislocation density of 10 6 cm -2 which exhibited a theoretical conversion efficiency of greater than 29% at AM1.5G spectrum, indicating a path for viable III-V multijunction cell technology on Si.Index Terms -III-V semiconductor materials, charge carrier lifetime, epitaxial layers, photovoltaic cells, semiconductor device modeling, short circuit currents, silicon.

The epitaxial growth of high efficiency inverted metamorphic triple junction solar cell for CPV application

“…6,7 The band gap-voltage offset is a key indicator of the quality and suppression of Shockly-Read-Hall recombination in semiconductors of variable band gap, where lower offset values are desired, since it is a measure of the separation between electron and hole quasi-Fermi levels as well as the conduction and valence band edges. 8 Here the band gap offset of the GaInAs subcell is 0.41 V at one sun, reflecting the long minority-carrier lifetime that can be achieved in metamorphic materials 9 . Under the AM1.5d, 1000 suns conditions, the I-V parameter comparison between IMM and LM solar cells is summarized in the Table I.…”

Epitaxy and characterization of AlGaInP-based LEDs on Si substrates for visible-spectrum light emission

“…is a minority lifetime-dependent parameter and minority lifetime and diffusion length are usually limited by a high TDD [52,127], the large J02 of the LED on undoped Ge/Si indicated the presence of high TDD in the LED junction. In addition, due to the poor materials quality, the LED on undoped Ge/Si shows a high ideality factor of 5.3.…”