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Title: Flexible nanomembrane photonic-crystal cavities for tensilely strained-germanium light emission

Abstract

Flexible photonic-crystal cavities in the form of Si-column arrays embedded in polymeric films are developed on Ge nanomembranes using direct membrane assembly. The resulting devices can sustain large biaxial tensile strain under mechanical stress, as a way to enhance the Ge radiative efficiency. Pronounced emission peaks associated with photonic-crystal cavity resonances are observed in photoluminescence measurements. These results show that ultrathin nanomembrane active layers can be effectively coupled to an optical cavity, while still preserving their mechanical flexibility. Thus, they are promising for the development of strain-enabled Ge lasers, and more generally uniquely flexible optoelectronic devices.

Authors:
; ;  [1]; ; ;  [2]
  1. Department of Electrical and Computer Engineering and Photonics Center, Boston University, 8 Saint Mary's Street, Boston, Massachusetts 02215 (United States)
  2. Department of Materials Science and Engineering, University of Wisconsin – Madison, 1509 University Avenue, Madison, Wisconsin 53706 (United States)
Publication Date:
OSTI Identifier:
22590776
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 108; Journal Issue: 24; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; CRYSTALS; EFFICIENCY; FILMS; FLEXIBILITY; GERMANIUM; LASERS; LAYERS; MEMBRANES; OPTOELECTRONIC DEVICES; PEAKS; PHOTOLUMINESCENCE; RESONANCE; STRAINS; STRESSES; VISIBLE RADIATION

Citation Formats

Yin, Jian, Wang, Xiaowei, Paiella, Roberto, Cui, Xiaorui, Sookchoo, Pornsatit, and Lagally, Max G. Flexible nanomembrane photonic-crystal cavities for tensilely strained-germanium light emission. United States: N. p., 2016. Web. doi:10.1063/1.4954188.
Yin, Jian, Wang, Xiaowei, Paiella, Roberto, Cui, Xiaorui, Sookchoo, Pornsatit, & Lagally, Max G. Flexible nanomembrane photonic-crystal cavities for tensilely strained-germanium light emission. United States. doi:10.1063/1.4954188.
Yin, Jian, Wang, Xiaowei, Paiella, Roberto, Cui, Xiaorui, Sookchoo, Pornsatit, and Lagally, Max G. 2016. "Flexible nanomembrane photonic-crystal cavities for tensilely strained-germanium light emission". United States. doi:10.1063/1.4954188.
@article{osti_22590776,
title = {Flexible nanomembrane photonic-crystal cavities for tensilely strained-germanium light emission},
author = {Yin, Jian and Wang, Xiaowei and Paiella, Roberto and Cui, Xiaorui and Sookchoo, Pornsatit and Lagally, Max G.},
abstractNote = {Flexible photonic-crystal cavities in the form of Si-column arrays embedded in polymeric films are developed on Ge nanomembranes using direct membrane assembly. The resulting devices can sustain large biaxial tensile strain under mechanical stress, as a way to enhance the Ge radiative efficiency. Pronounced emission peaks associated with photonic-crystal cavity resonances are observed in photoluminescence measurements. These results show that ultrathin nanomembrane active layers can be effectively coupled to an optical cavity, while still preserving their mechanical flexibility. Thus, they are promising for the development of strain-enabled Ge lasers, and more generally uniquely flexible optoelectronic devices.},
doi = {10.1063/1.4954188},
journal = {Applied Physics Letters},
number = 24,
volume = 108,
place = {United States},
year = 2016,
month = 6
}
  • Mechanically stressed nanomembranes are used to demonstrate mid-infrared interband light emission from Ge within the 2.1–2.5 μm atmospheric transmission window. Large biaxial tensile strain is introduced in these samples to convert Ge into a (near-) direct-bandgap semiconductor and to red-shift its luminescence. A diffractive array of Ge pillars is used to outcouple the long-wavelength interband radiation, which is otherwise primarily emitted in the sample plane. An order-of-magnitude strain-induced enhancement in radiative efficiency is also reported, together with the observation of luminescence signatures associated with photonic-crystal cavity modes. These results are promising for the development of silicon-compatible lasers for mid-infrared optoelectronicsmore » applications.« less
  • We demonstrate flexible Ge nanomembrane (Ge NM) based metal-semiconductor-metal photodiodes. The effect of uniaxial tensile strain on Ge NM based photodiodes was investigated using bending fixtures. Dark current density is decreased from 21.5 to 4.8 mA/cm{sup 2} at 3 V by a tensile strain of 0.42% while photon responsivity is increased from 0.2 to 0.45 A/W at the wavelength of 1.5 μm. Enhanced responsivity is also observed at longer wavelengths up to 1.64 μm. The uniaxial tensile strain effectively reduces the direct bandgap energy of the Ge NM, leading to a shift of the absorption edge toward a longer wavelength.
  • We have designed, fabricated and characterized a nanomembrane which could be used as a moving end mirror of a Fabry-Perot cavity. The high reflectivity and optimized mechanical properties of the membrane should allow us to demonstrate the mechanical ground state of the membrane. As any sub-micron mechanical resonator, our system demonstrates nonlinear dynamical effects. We characterize the mechanical response to a strong pump drive and observe a shift in the oscillation frequency and phase conjugation of the mechanical mode. Such nonlinear effects are expected to play a role in the quantum dynamics of the membrane as well.
  • No abstract prepared.