Efficient silicon solar cells with dopant-free asymmetric heterocontacts

James Bullock, Mark Hettick, Jonas Geissbuhler, Alison J. Ong, Thomas Allen, Carolin M. Sutter-Fella, Teresa Chen, Hiroki Ota, Ethan W. Schaler, Stefaan De Wolf, Christophe Ballif, Andres Cuevas, Ali Javey*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

A salient characteristic of solar cells is their ability to subject photo-generated electrons and holes to pathways of asymmetrical conductivity-'assisting' them towards their respective contacts. All commercially available crystalline silicon (c-Si) solar cells achieve this by making use of doping in either near-surface regions or overlying silicon-based films. Despite being commonplace, this approach is hindered by several optoelectronic losses and technological limitations specific to doped silicon. A progressive approach to circumvent these issues involves the replacement of doped-silicon contacts with alternative materials which can also form 'carrier-selective' interfaces on c-Si. Here we successfully develop and implement dopant-free electron and hole carrier-selective heterocontacts using alkali metal fluorides and metal oxides, respectively, in combination with passivating intrinsic amorphous silicon interlayers, resulting in power conversion efficiencies approaching 20%. Furthermore, the simplified architectures inherent to this approach allow cell fabrication in only seven low-temperature (

Original languageEnglish
Article number15031
Number of pages7
JournalNature Energy
Volume1
DOIs
StatePublished - Jan 25 2016
Externally publishedYes

Keywords

  • N-TYPE SILICON
  • ELECTRON INJECTION
  • REAR CONTACTS
  • MOLYBDENUM
  • DEVICES
  • LAYER
  • WAFER
  • MOO3
  • FILM

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