title: 1300 nm wavelength InAs quantum dot photodetector grown on silicon.
abstract: The optical and electrical properties of InAs quantum dots epitaxially grown on a silicon substrate have been investigated to evaluate their potential as both photodiodes and avalanche photodiodes (APDs) operating at a wavelength of 1300 nm. A peak responsivity of 5 mA/W was observed at 1280 nm, with an absorption tail extending beyond 1300 nm, while the dark currents were two orders of magnitude lower than those reported for Ge on Si photodiodes. The diodes exhibited avalanche breakdown at 22 V reverse bias which is probably dominated by impact ionisation occurring in the GaAs and AlGaAs barrier layers. A red shift in the absorption peak of 61.2 meV was measured when the reverse bias was increased from 0 to 22 V, which we attributed to the quantum confined stark effect. This shift also leads to an increase in the responsivity at a fixed wavelength as the bias is increased, yielding a maximum increase in responsivity by a factor of 140 at the wavelength of 1365 nm, illustrating the potential for such a structure to be used as an optical modulator.
authors.affiliation: Department of Electronic and Electrical Engineering, University of Sheffield, Sheffield, UK. i.sandall@Sheffield.ac.uk
authors.forename: Ian
authors.initials: I
authors.lastname: Sandall
authors.forename: Jo Shien
authors.initials: JS
authors.lastname: Ng
authors.forename: John P R
authors.initials: JP
authors.lastname: David
authors.forename: Chee Hing
authors.initials: CH
authors.lastname: Tan
authors.forename: Ting
authors.initials: T
authors.lastname: Wang
authors.forename: Huiyun
authors.initials: H
authors.lastname: Liu
mesh_terms: D000042:Absorption; D001152:Arsenicals / Q000737:chemistry*; D005857:Germanium / Q000737:chemistry*; D007204:Indium / Q000737:chemistry*; D008422:Materials Testing; D046529:Microscopy, Electron, Transmission / Q000379:methods; D036103:Nanotechnology / Q000379:methods; D055095:Optics and Photonics; D010777:Photochemistry / Q000379:methods*; D045663:Quantum Dots; D011789:Quantum Theory; D012825:Silicon / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D001152:Arsenicals; D005857:Germanium; D007204:Indium; C076773:indium arsenide; D012825:Silicon