Development of (Si)5-2y(III-V)y alloys for photovoltaic applications

Project: Research project

Description

1.0 BACKGROUND Theoretical work at the National Renewable Energy Laboratory (NREL) recently indicated that (Si)5- 2y(III-V)y alloy systems would be a lattice-matched, single-phase material with a suitable band gap and absorption for high performance top junctions of a tandem solar cell. Previously, metastable (III-V)-IV alloys were grown by sputtering, evaporation, or vapor phase deposition, but film quality was poor due to phase separation. Recently, Arizona State University (ASU) grew epitaxial Si3AlP and other (Si)5-2y(IIIV) y using specially designed molecular precursors that fix the film stoichiometry and eliminate phase separation. This exciting class of semiconductors opens wide possibilities for lattice matching and bandgap engineering. Photovoltaic (PV) applications include new top cell absorbers, buffer layers, and Si passivation. The Silicon group at NREL will develop and grow new (Si)5-2y(III-V)y alloys for solar cell applications. 2.0 OBJECTIVE The objective of this subcontract is to 1) develop and refine procedures/precursors and deposition protocols for growing novel (Si)5-2y(III-V)y alloys for solar cell applications; and 2) grow thin, epitaxial layers of (Si)5-2y(III-V)y alloys to support detailed characterization of the films and solar cell development. 3.0 SCOPE OF WORK ASU will synthesize new precursor molecules for growing (Si)5-2y(III-V)y alloys. These precursors will then be used to grow thin films on Si and other substrates. Films will be sent to NREL for characterization and device processing. The Subcontractor will also advise NREL on its in-house reactor construction.
StatusFinished
Effective start/end date6/3/133/13/15

Funding

  • US Department of Energy (DOE): $300,860.00

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renewable energy
solar cells
subcontracts
cells
fixing
passivity
stoichiometry
absorbers
buffers
sputtering
reactors
evaporation
engineering
vapor phases
silicon
thin films
molecules