Evolution of the photoconductance decay versus wavelength in silicon doped GaInAs

Photoconductance investigations with square light pulses have been made on semiconducting thin films of GaInAs doped with silicon. Two wavelengths are used: 870 and 1300 nm. One unexpected evolution of the photoconductance transients resulting from traps is observed when the wavelength is varied. A model based on the representation of each trap by a well located between two disymmetrical potential barriers is consistent with the experimental results.