Optics of excitons in InGaAs/InP quantum wells

We report on the analysis of the structures with In/sub 0.53/Ga/sub 0.47/As/InP quantum wells (QW) for use in tunable resonant cavity enhanced photodetectors operating at a wavelength of 1550 nm. The structures were prepared by low-pressure MOVPE. The optical properties were analysed by spectral ellipsometry, photoluminescence and photocurrent measurements. The excitonic transition energies are slightly shifted to lower values in comparison with theoretical model. This difference can be explained by the formation of InAs or InAsP monolayer at the interface between InGaAs QW and InP barrier. For the MQW PIN diode with 20 wells we measured a Stark shift of 20 meV at an applied electric field of 10 V/im.