Use of the photoluminescence intensity variation as an in-situ probe for electrochemical copper deposition on a p-type GaAs electrode

Photoluminescence was used as an in-situ method for following the electrodeposition of copper on p-type GaAs electrodes from a 0.5 M H₂SO₄ solution containing Cu(II) sulphate. The method appeared to be very sensitive to copper coating and to be able to detect a copper amount of the monolayer range. Moreover, during anodic polarisation of the metallised electrode, photoluminescence measurements showed the complete dissolution of the copper layer. In-situ photoluminescence measurements were confirmed by ex-situ analyses at different stages of the electrochemical treatment of the GaAs electrode.