Enhanced Bifaciality Factor with Sb2Se3 Devices Modeling Cu2O Back Buffer

Sanghyun Lee, Kent Price

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review


We have investigated bifacial Ge-incorporated Sb2Se3 thin-film solar cells by modeling and simulating a back buffer layer including Cu2O to optimize the performance of bifacial devices. We proposed Ge-incorporated Sb2Se3 absorber layers for bifacial devices, which were used as modeling input parameters after characterizing the absorber film. With extracted parameters (bandgap, 1.23 eV and the absorption coefficient, 3 × 105 cm-1at 600 nm), we investigated the impact of various back buffer layers on bifacial device performance. The simulated device structure is ZnO:Al/i-ZnO/CdS/Ge-Sb2Se3/back buffer layer/TCO. First, the impact of conduction and valence band offsets was investigated, showing the significant dependence of device performance on valence band offset. To minimize the Schottky hole barrier at the back contact region, high back buffer doping concentration (1 × 1015cm-3or higher) is required to improve device performance, whereas low absorber doping concentration (<1 × 1014cm-3) enables higher efficiency due to the enlarged energy band bending. With a Cu2O back buffer layer, the best efficiency of front-side illumination is 19.7 %, Voc (744.4 mV), Jsc (40.14 mA/cm2), and FF (66.1 %) and that of the rear-side illumination is 13.0 %, Voc (724.5 mV), Jsc (31.6 mA/cm2), and FF (56.7 %). Consequently, the bifaciality factor is 66 %.

Original languageEnglish
Title of host publication2023 IEEE 50th Photovoltaic Specialists Conference, PVSC 2023
ISBN (Electronic)9781665460590
StatePublished - 2023
Event50th IEEE Photovoltaic Specialists Conference, PVSC 2023 - San Juan, United States
Duration: Jun 11 2023Jun 16 2023

Publication series

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


Conference50th IEEE Photovoltaic Specialists Conference, PVSC 2023
Country/TerritoryUnited States
CitySan Juan

Bibliographical note

Publisher Copyright:
© 2023 IEEE.


  • Ge
  • SbSe
  • bifacial solar cells
  • modeling

ASJC Scopus subject areas

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


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