In this paper we present a detailed study of the intersubband absorption occurring between electron states confined in strained Ge multi-quantum wells as a function of the temperature. The high structural quality of the samples is reflected by the very narrow absorption line-shape constant with temperature. We observe a temperature driven charge transfer occurring between the ground and the first excited subband which, in turn, induces a change in the depolarization shift and consequently in the energy of the absorbance peak. The experimental observations are well accounted for by a multi-valley k·p model.

Download full-text PDF

Source
http://dx.doi.org/10.1088/0957-4484/23/46/465708DOI Listing

Publication Analysis

Top Keywords

multi-quantum wells
8
depolarization shift
8
narrow intersubband
4
intersubband transitions
4
transitions n-type
4
n-type ge/sige
4
ge/sige multi-quantum
4
wells control
4
control terahertz
4
terahertz absorption
4

Similar Publications

Vertical thin-film light-emitting diode (VTF-LED) adopts a GaN thin-film structure that confines light via the top GaN-air and the bottom GaN-metal interfaces. Such interfaces provide significantly higher optical reflectivity to promote optical confinement. As the structures are cladding-less, VTF-LED can be processed from simpler epitaxial structures comprising a p-n junction and the multi-quantum wells, directly leading to facile fabrication and lower manufacturing costs.

View Article and Find Full Text PDF

Ultra-dense Green InGaN/GaN Nanoscale Pixels with High Luminescence Stability and Uniformity for Near-Eye Displays.

ACS Nano

October 2024

Centre Energie, Matériaux et Télécommunications, Institut national de la recherche scientifique (INRS-EMT), Varennes, Québec J3X 1P7, Canada.

Ultra-dense (>4,000 pixels per inch) and highly stable full-color III-nitride nanoscale pixels are crucial for near-eye display technologies like virtual and augmented-reality glasses. In this context, InGaN-based long wavelength green microscale light-emitting diodes face major bottlenecks, such as low efficiency and inadequate wavelength stability. These challenges are associated with the presence of both nonradiative surface defects and the strain induced quantum-confined Stark effect.

View Article and Find Full Text PDF

Telecom-band multiwavelength vertical emitting quantum well nanowire laser arrays.

Light Sci Appl

September 2024

Department of Electronic Materials Engineering, Research School of Physics, The Australian National University, Canberra, ACT 2600, Australia.

Highly integrated optoelectronic and photonic systems underpin the development of next-generation advanced optical and quantum communication technologies, which require compact, multiwavelength laser sources at the telecom band. Here, we report on-substrate vertical emitting lasing from ordered InGaAs/InP multi-quantum well core-shell nanowire array epitaxially grown on InP substrate by selective area epitaxy. To reduce optical loss and tailor the cavity mode, a new nanowire facet engineering approach has been developed to achieve controlled quantum well nanowire dimensions with uniform morphology and high crystal quality.

View Article and Find Full Text PDF

Low-Polarization, Broad-Spectrum Semiconductor Optical Amplifiers.

Nanomaterials (Basel)

June 2024

State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China.

Polarization-insensitive semiconductor optical amplifiers (SOAs) in all-optical networks can improve the signal-light quality and transmission rate. Herein, to reduce the gain sensitivity to polarization, a multi-quantum-well SOA in the 1550 nm band is designed, simulated, and developed. The active region mainly comprises the quaternary compound InGaAlAs, as differences in the potential barriers and wells of the components cause lattice mismatch.

View Article and Find Full Text PDF
Article Synopsis
  • InGaN-based long wavelength laser diodes (LDs) on silicon are crucial for advancements in laser display and lighting technologies.
  • Effective interface engineering of InGaN multi-quantum wells (MQWs) is critical to prevent issues like photon scattering and internal absorption losses that limit the lasing wavelength.
  • This study reports improvements in the morphology and interface sharpness of InGaN layers using a graded-composition waveguide and a thin AlGaN layer, leading to the successful fabrication of a cyan LD emitting at 480 nm with a low threshold current density of 18.3 kA/cm.
View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!