Strain-Induced Pseudoheterostructure Nanowires Confining Carriers at Room Temperature with Nanoscale-Tunable Band Profiles

• Published in: Nano letters Vol. 13; no. 7; pp. 3118 - 3123
• Main Authors: Nam, Donguk, Sukhdeo, David S, Kang, Ju-Hyung, Petykiewicz, Jan, Lee, Jae Hyung, Jung, Woo Shik, Vučković, Jelena, Brongersma, Mark L, Saraswat, Krishna C
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 10.07.2013
• Subjects: Carriers; Condensed matter: structure, mechanical and thermal properties; Constraining; Cross-disciplinary physics: materials science; rheology; Electronics; Exact sciences and technology; Heterostructures; Low-dimensional structures (superlattices, quantum well structures, multilayers): structure, and nonelectronic properties; Materials science; Methods of nanofabrication; Nanocrystalline materials; Nanolithography; Nanoscale materials and structures: fabrication and characterization; Nanostructure; Nanowires; Photonics; Physics; Quantum wires; Semiconductors; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); pseudoheterostructure; photoluminescence; germanium; heterostructure; Strain; nanowire; Nanometer scale; Confinement; Semiconductor materials; Wafers; Heterojunctions; Stress effects; Nanowires; Nanostructures; Nanolithography; Nanostructured materials; Heterostructures
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/nl401042n

Semiconductor heterostructures play a vital role in photonics and electronics. They are typically realized by growing layers of different materials, complicating fabrication and limiting the number of unique heterojunctions on a wafer. In this Letter, we present single-material nanowires which behave exactly like traditional heterostructures. These pseudo­heterostructures have electronic band profiles that are custom-designed at the nanoscale by strain engineering. Since the band profile depends only on the nanowire geometry with this approach, arbitrary band profiles can be individually tailored at the nanoscale using existing nanolithography. We report the first experimental observations of spatially confined, greatly enhanced (>200×), and wavelength-shifted (>500 nm) emission from strain-induced potential wells that facilitate effective carrier collection at room temperature. This work represents a fundamentally new paradigm for creating nanoscale devices with full heterostructure behavior in photonics and electronics.