Epitaxial GaAsP/Si Tandem Solar Cells with Integrated Light Trapping

S. Fan, Z. Yu, Y. Sun, W. Weigand, P. Dhingra, M. Kim, R. D. Hool, E. D. Ratta, Z. C. Holman, M. L. Lee

Research output: Chapter in Book/Report/Conference proceedingConference contribution

4 Scopus citations


We investigate the effect of Si random pyramid texturing on 1.7eV/1.1eV GaAs0.77P0.23/Si 2-terminal tandem solar cells (hereafter GaAsP/Si). Due to the light trapping effect, rear surface texturing increases the short-circuit current density of the Si bottom cell by 2.76 mA/cm2 relative to an untextured cell. For the GaAsP top cell, we investigate the use of lattice-matched AlGaAsP as the back surface field (BSF) layer and also as an intermediate barrier between the n-GaAsP emitter and n-AlInP window. Despite parasitic absorption in the n-AlGaAsP barrier, our 1.0 cm2 GaAsP/Si tandem cell with backside textured Si bottom cell exhibits an NREL-certified AM1.5G efficiency of 18.7%. A reduction of device area from 1.0 cm2 to 0.13 cm2 results in an efficiency of 19.5% due to lower series resistance. Development of >20%-efficient tandem cells is ongoing.

Original languageEnglish (US)
Title of host publication2019 IEEE 46th Photovoltaic Specialists Conference, PVSC 2019
PublisherInstitute of Electrical and Electronics Engineers Inc.
Number of pages4
ISBN (Electronic)9781728104942
StatePublished - Jun 2019
Event46th IEEE Photovoltaic Specialists Conference, PVSC 2019 - Chicago, United States
Duration: Jun 16 2019Jun 21 2019

Publication series

NameConference Record of the IEEE Photovoltaic Specialists Conference
ISSN (Print)0160-8371


Conference46th IEEE Photovoltaic Specialists Conference, PVSC 2019
Country/TerritoryUnited States


  • GaAsP
  • epitaxial III-V/Si integration
  • light trapping
  • metamorphic growth
  • tandem

ASJC Scopus subject areas

  • Control and Systems Engineering
  • Industrial and Manufacturing Engineering
  • Electrical and Electronic Engineering


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