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Zn₃P₂ and Cu₂O Substrates for Solar Energy Conversion


Kimball, Gregory Michael (2012) Zn₃P₂ and Cu₂O Substrates for Solar Energy Conversion. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/Q4F1-H538.


Zinc phosphide (Zn3P2) and cuprous oxide (Cu2O) are promising and earth-abundant alternatives to traditional thin film photovoltaics materials such as CIGS, CdTe, and a-Si. We have prepared high purity substrates of Zn3P2 from elemental zinc and phosphorus, and Cu2O by the thermal oxidation of copper foils, to investigate their fundamental material properties and potential for solar energy conversion. Photoluminescence-based measurements of Zn3P2 substrates have revealed a fundamental indirect band gap at 1.38 eV and a direct band gap at 1.50 eV, with time-resolved data indicating minority carrier diusion lengths of ≥7 μm. Solar cells based on Mg/Zn3P2 junctions with solar energy conversion efficiency reaching 4.5% were examined by composition profiling to elucidate the passivation reaction between Mg metal and Zn3P2 surfaces. Semiconductor/liquid junctions incorporating Cu2O substrates exhibited open-circuit voltage, Voc, values in excess of 800 mV and internal quantum yields approaching 100% in the 400–500 nm spectral range.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:zinc phosphide, cuprous oxide, photovoltaics, photoelectrochemistry, surface chemistry, diffusion length
Degree Grantor:California Institute of Technology
Division:Chemistry and Chemical Engineering
Major Option:Chemistry
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Atwater, Harry Albert (advisor)
  • Lewis, Nathan Saul (advisor)
Thesis Committee:
  • Gray, Harry B. (chair)
  • Okumura, Mitchio
  • Miller, Thomas F.
  • Atwater, Harry Albert
  • Lewis, Nathan Saul
Defense Date:27 September 2011
Funding AgencyGrant Number
Dow Chemical CompanyUNSPECIFIED
Department of Energy(DE-FG02-03ER15483)
Department of Energy(DE-FG36-08GO18006)
Record Number:CaltechTHESIS:10302011-182613259
Persistent URL:
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URLURL TypeDescription DOIPortions of article adapted for thesis of article adapted for thesis of article adapted for thesis of article adapted for thesis
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:6723
Deposited By: Gregory Kimball
Deposited On:10 Dec 2013 00:21
Last Modified:08 Nov 2023 00:12

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