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

Abstract

Considering tensile-strained p-type Si/Si 1−y Ge y quantum wells grown on a relaxed Si 1−x Ge x (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.

Interlevel optical transitions in Si/Ge x Si1−x /Si quantum wells

“…Thus, the main conclusion that light absorption increases in tensile strained heterostructures with QWs as compared with compressed wells can be questioned. Ge/Si heterostructures with QWs formed on relaxed buffer Ge y Si 1 − y layers are studied in [4], where a comparison is made of Ge/Si heterostructures with QWs having compressive or tensile strains, but comparison of the intersubband optical transition intensities for different types of heterostructures are not compared.…”