Photocurrent and photoluminescence studies of resonant tunneling diodes

We have investigated transport and optical properties in GaAs–Al0.35Ga0.65As double-barrier diodes. We have observed an unexpected enhancement of the integrated photoluminescence (PL) intensity and photocurrent (PC) with increasing temperature. For the integrated PL intensity, this enhancement is followed by an expected decrease at higher temperatures once effective nonradiative mechanisms become activated. The observed behavior in the photocurrent is associated to the dependence of hole mobility on the temperature. We have developed a model to fit the integrated PL intensity that combines the effects of the density of minority carriers (holes) generated at the contact and the dependence of hole mobility on the temperature. The minority carrier mobility is obtained from PC measurements.