title: Influence of delta-doping on the hole capture probability in Ge/Si quantum dot mid-infrared photodetectors.
abstract: We study the effect of delta-doping on the hole capture probability in ten-period p-type Ge quantum dot photodetectors. The boron concentration in the delta-doping layers is varied by either passivation of a sample in a hydrogen plasma or by direct doping during the molecular beam epitaxy. The devices with a lower doping density is found to exhibit a lower capture probability and a higher photoconductive gain. The most pronounced change in the trapping characteristics upon doping is observed at a negative bias polarity when the photoexcited holes move toward the δ-doping plane. The latter result implies that the δ-doping layers are directly involved in the processes of hole capture by the quantum dots.
authors.affiliation: Rzhanov Institute of Semiconductor Physics, Siberian Branch of the Russian Academy of Science, 630090 Novosibirsk, Russia ; Tomsk State University, 634050 Tomsk, Russia.
authors.forename: Andrew
authors.initials: A
authors.lastname: Yakimov
authors.affiliation: Rzhanov Institute of Semiconductor Physics, Siberian Branch of the Russian Academy of Science, 630090 Novosibirsk, Russia.
authors.forename: Victor
authors.initials: V
authors.lastname: Kirienko
authors.affiliation: Rzhanov Institute of Semiconductor Physics, Siberian Branch of the Russian Academy of Science, 630090 Novosibirsk, Russia.
authors.forename: Vyacheslav
authors.initials: V
authors.lastname: Timofeev
authors.affiliation: Rzhanov Institute of Semiconductor Physics, Siberian Branch of the Russian Academy of Science, 630090 Novosibirsk, Russia.
authors.forename: Aleksei
authors.initials: A
authors.lastname: Bloshkin
authors.affiliation: Rzhanov Institute of Semiconductor Physics, Siberian Branch of the Russian Academy of Science, 630090 Novosibirsk, Russia.
authors.forename: Anatolii
authors.initials: A
authors.lastname: Dvurechenskii
keywords: Germanium; Infrared photodetectors; Interband transitions; Quantum dots; Silicon