Technique for producing "good" GaAs solar cells using poor-quality substrates

Relatively good GaAs solar cells can be made from poor-quality substrates by making the junction deep (≳1 μ) instead of shallow and by "leaching" both the pGaAs and nGaAs regions during the growth process. AM0 efficiencies of 14.7% (19% AM1) have been obtained from substrates with starting substrate diffusion lengths of 0.6 μ.