## Abstract

Epitaxial layers of n-GaAs_{1-x}P_{x} (0 < x < 1) have been studied as photoelectrodes and as Au Schottky junctions. We observe increases in open-circuit voltage, V_{oc}, with increases in P content for n-GaAs_{1-x}P_{x} (x ≤ 0.4) and decreases in V_{oc} for ≤ 0.6. Under 88 mW/cm^{2} of ELH-type.(3350 K color temperature with a dichroic rear reflector) tungsten-halogen irradiation, we observe that n-GaAs_{0.72}P_{0.28} anodes exhibit a V_{oc} of 0.95-0.99 V, short-circuit currents of 15-17 mA/cm^{2}, and energy conversion efficiencies of 13.0 ± 1.0%. Irradiation at 632.8-nm yields monochromatic conversion efficiencies of greater than 30%, and solar irradiation (85-100 mW/cm^{2}) yields efficiencies of 11.0 ± 1.0% in 1.0 M KOH/1.0 M Se^{2-}/0.-01 M Se_{2}^{2-} solutions. The n-GaAs_{0.72}P_{0.28} anodes exhibit stable photocurrent for passage of over 3000 C/cm^{2} at AM1 photocurrent densities. Ru(H_{2}O)_{6}^{3+} ions are effective in improving photocurrent-voltage characteristics for H-GaAs_{1-x}P_{x} (0 ≤ x < 1) anodes but have no effect for n-GaP, indicating chemical interactions of the Ru ion with As or As oxide sites at the semiconductor/liquid junction. Direct comparison of V_{oc} for n-GaAs_{1-x}P_{x}/Au junctions with n-GaAs_{1-x}P_{x}/Se^{2-} barriers indicates that liquid junctions have higher V_{oc} values than some Schottky barriers and that pinning of the Fermi level by intrinsic surface states may not play a dominant role in determining interface parameters for these junctions.

Original language | English |
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Pages (from-to) | 1310-1317 |

Number of pages | 8 |

Journal | Journal of physical chemistry |

Volume | 88 |

Issue number | 7 |

DOIs | |

Publication status | Published - 1984 |

## ASJC Scopus subject areas

- Engineering(all)
- Physical and Theoretical Chemistry