Metal-oxide-semiconductor SiGe/Si quantum dot infrared photodetectors with delta doping in different positions

Boron was delta (δ) introduced in SiGe/Si quantum dots (the δ-QD sample) or Si spacers (the δ-spacer sample) in SiGe/Si quantum dot infrared photodetectors (QDIPs) to provide the quantum dots with a sufficient hole concentration for infrared excitation. The influence on dark currents due to the different positions of δ-doping layers is studied. The current mechanisms of the δ-QD sample and the δ-spacer sample in metal-oxide-semiconductor structures are discussed. It is found that the positions of δ-doping layers should depend on the applications of QDIPs.