Preliminary design of a tensile-strained p-type Si/SiGe quantum well infrared photodetector

Considering tensile-strained p-type Si/Si1−yGey quantum wells grown on a relaxed Si1−xGex (0 0 1) virtual substrate (y < x), the hole subband structure and the effective masses of the first bound hole state in the quantum wells are calculated by using the 6 × 6 k . p method. Designs for tensile-strained p-type quantum well infrared photodetectors (QWIPs) based on the bound-to-quasi-bound transitions are discussed, which are expected to retain the ability of coupling normally incident infrared radiation without any grating couplers, have lower dark current than n-type QWIPs and also have a larger absorption coefficient and better transport characteristics than normal unstrained or compressive-strained p-type QWIPs