Germanium Nanocrystal Properties from Photoluminescence. (16th August 2021)

• Record Type: Journal Article
• Authors: Rowell, Nelson L.; Lockwood, David J.
• Is Part Of: ECS journal of solid state science and technology. Volume 10:Number 8(2021)
• Publication Date: 2021-08-16
• Subjects: Solid state chemistry -- Periodicals; Electronics -- Materials -- Periodicals; Electrochemistry -- Periodicals; 541.0421
• DOI: 10.1149/2162-8777/ac1c59
• Languages: English
• ISSNs: 2162-8777

Abstract

Abstract : Morphological information has been obtained using the strong near-infrared photoluminescence emitted by germanium (Ge) nanocrystals (NCs) coherently imbedded in SiGe alloy layers, grown by molecular beam epitaxy on Si substrates. The emission spectra are analyzed for the effects of strain, carrier confinement, and disorder over a wide range of Ge concentrations in the surrounding SiGe medium. This analysis provided significant insight into the properties of the Ge nanocrystals, including their size and shape. We also discuss the mechanisms leading to the high quantum efficiency observed for emission from the Ge nanocrystals at low temperatures. We indicate how direct gap behavior might be achieved for Ge NCs lattice matched within dilute Ge1-y Sny alloys, where tensile strain would be present in the NCs in all three directions.