Improved carrier collection in intermixed InGaAs/GaAs quantum wells

We have used photoluminescence up conversion to study the carrier capture t imes into intermixed InGaAs/GaAs quantum wells. We have found that the capt ure into the intermixed wells is markedly faster than capture into the refe rence (unintermixed) quantum wells. The reasons for the significant reducti on in the capture time is related to the shape of the intermixed quantum we ll. Such a reduction in the capture time is beneficial both in terms of the quantum efficiency and the frequency response of intermixed optoelectronic devices. (C) 1998 American Institute of Physics. [S0003-6951(98)01849-X].