Photocurrent generation in semiconducting films of finite thickness

Photocurrent generation in semiconducting films of finite thickness 

Examples of internal photoemission at oxide-covered metal electrodes are considered later in this chapter. 

Equation 6(a) reduces to several useful limiting forms. 

Although space-charge recombination may not be important for single crystal semiconductors, high densities of defects and impurities are expected to be present in anodic films on metal electrodes and recombination may 

If the film contains a high density of impurity states that act as electron donors or acceptors, the space-charge region may become thinner than the film itself. A more general expression for the photocurrent coversion efficiency that takes this possibility into account can be derived if the simplifying assumption is made that the diffusion length of minority carriers is likely to be small in polycrystalline or amorphous films that contain high densities of recombination centres 

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