Saturation photoconductivity inCdIn2S4

At excitation energies corresponding to definite extrinsic transitions in ${\mathrm{CdIn}}_2$ ${\mathrm{S}}_4$, the photoconductivity is investigated as a function of light intensity over a maximum of 12 orders of magnitude ${(10\mathrm{}}^{16}$ to ${10}^{28}$ photons/${\mathrm{m}}^2$ sec). For certain wavelength ranges a photoconductivity plateau is observed at high excitation intensities. This saturation effect is attributed to a saturation of high density levels within the gap at high light intensities.