Uniformly doped InAs/GaAs quantum-dot infrared photodetector structures

We have studied InAs/GaAs quantum-dot photodetector devices that are sensitive to normal incidence radiation. Photoluminescence measurements indicate that there are three bound states within the conduction band of the quantum dots. The detector structures were uniformly doped to supply approximately 9 electrons per dot. The peak of the photoresponse spectrum is observed at about 5.12 mu m. In general the characteristics of our devices are similar to those where the dopant impurities are placed within the wetting layer or just below the quantum dots. (c) 2005 American Vacuum Society.