title: Room-temperature efficient light detection by amorphous Ge quantum wells.
abstract: In this work, ultrathin amorphous Ge films (2 to 30 nm in thickness) embedded in SiO2 layers were grown by magnetron sputtering and employed as proficient light sensitizer in photodetector devices. A noteworthy modification of the visible photon absorption is evidenced due to quantum confinement effects which cause both a blueshift (from 0.8 to 1.8 eV) in the bandgap and an enhancement (up to three times) in the optical oscillator strength of confined carriers. The reported quantum confinement effects have been exploited to enhance light detection by Ge quantum wells, as demonstrated by photodetectors with an internal quantum efficiency of 70%.
authors.affiliation: MATIS IMM-CNR and Dipartimento di Fisica e Astronomia, Università di Catania, via S, Sofia 64, Catania 95123, Italy. salvatore.cosentino@ct.infn.it.
authors.forename: Salvatore
authors.initials: S
authors.lastname: Cosentino
authors.forename: Maria
authors.initials: M
authors.lastname: Miritello
authors.forename: Isodiana
authors.initials: I
authors.lastname: Crupi
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Nicotra
authors.forename: Francesca
authors.initials: F
authors.lastname: Simone
authors.forename: Corrado
authors.initials: C
authors.lastname: Spinella
authors.forename: Antonio
authors.initials: A
authors.lastname: Terrasi
authors.forename: Salvatore
authors.initials: S
authors.lastname: Mirabella