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Photoelectrochemical Cell: Can they work with external potential?

  1. Mar 22, 2015 #1
    Photoelectrochemical Cell for water splitting with semi conducting photoanode (TiO2) and metal counter electrode (Pt).

    A photoelectrochemical cell under UV illumination generates a photocurrent. This photocurrent can be increased by applying an external bias because of improved exciton splitting.

    No photocurrent is observed if there is no UV illumination and no external bias.

    My question is: Can a photocurrent be generated with an external bias and no UV illumination?

  2. jcsd
  3. Mar 27, 2015 #2
    By definition: Photocurrent is the electric current through a photosensitive device, such as a photodiode, as the result of exposure to radiant power.

    Therefore, if there is no radiation on the cell, then no photocurrent will be produced. If you apply a potential across the cell, you will see a current generated since any electrode can split water as long as it is given enough energy. This current would not be classified as a photocurrent since it is not caused by external radiation on the cell.

    To summarize, a current can be produced by an external potential, but it will not be classified as a photocurrent unless there is illumination of the cell.
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