Self-assembled quantum dots embedded in semiconductor heterostructures have proved to be a rich system for exploring the physics of three dimensionally confined charges and excitons. We present here a novel structure, which allows adjusting the level of confinement between 3D and 2D for electrons and holes, respectively. The quantum post consists of a quantum dot connected to a short quantum wire. The molecular beam epitaxy deposition of these self-assembled structures is discussed, and their structural and chemical compositions are presented. Their optical properties measured by photoluminescence are compared to an eight-band strain-dependent k.p model incorporating detailed structure and alloy composition. The calculations show electron delocalization in the quantum wire part of the quantum post and hole localization in the strain-induced regions at the ends of the quantum post. The quantum post offers the possibility of controlling the dipole moment in the structure and opens up new means for tuning the intra-subband transitions by controlling its dimensions.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/nl070132r | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Nonvolatile Memory Device Based on the Ferroelectric Metal/Ferroelectric Semiconductor Junction.
Nano Lett
January 2025
Center for Spintronics and Quantum Systems, State Key Laboratory for Mechanical Behavior of Materials, School of Materials Science and Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China.
The ferroelectric tunnel junction (FTJ) is a competitive candidate for post-Moore nonvolatile memories due to its low power consumption and nonvolatility, with its performance being strongly dependent on the conditions for contact between the ferroelectric material and the metal electrode. The development of two-dimensional materials in recent years has offered new opportunities such as functional metal layers, which is challenging for traditional FTJ systems. Here, we introduce the newly discovered ferroelectric metal WTe as the electrode to construct WTe/α-InSe/Au ferroelectric semiconductor junctions.
View Article and Find Full Text PDFSmart luminescent materials have drawn a significant attention owing to their unique optical properties and versatility in sensor applications. These materials, encompassing a broad spectrum of organic, inorganic, and hybrid systems including quantum dots, organic dyes, and metal-organic frameworks (MOFs), offer tunable emission characteristics that can be engineered at the molecular or nanoscale level to respond to specific stimuli, such as temperature, pH, and chemical presence. Recent advancements have been driven by the integration of nanotechnology, which enhances the sensitivity and selectivity of luminescent materials in sensor platforms.
View Article and Find Full Text PDFQuantum state processing through controllable synthetic temporal photonic lattices.
Nat Photonics
October 2024
Institut national de la recherche scientifique, Centre Énergie Matériaux Télécommunications, Varennes, Quebec Canada.
Quantum walks on photonic platforms represent a physics-rich framework for quantum measurements, simulations and universal computing. Dynamic reconfigurability of photonic circuitry is key to controlling the walk and retrieving its full operation potential. Universal quantum processing schemes based on time-bin encoding in gated fibre loops have been proposed but not demonstrated yet, mainly due to gate inefficiencies.
View Article and Find Full Text PDFPost-Degradation Recovery of CsPbI Quantum Dot Solar Cells.
Small
January 2025
Chair for Emerging Electronic Technologies, TUD Dresden University of Technology, Nöthnitzer Straße 61, 01187, Dresden, Germany.
The stability of perovskite quantum dot solar cells is one of the key challenges of this technology. This study reveals the unique degradation behavior of cesium lead triiodide (CsPbI) quantum dot solar cells. For the first time, it is shown that the oxygen-induced degradation and performance loss of CsPbI quantum dot photovoltaic devices can be reversed by exposing the degraded samples to humidity, allowing the performance to recover and even surpass the initial performance.
View Article and Find Full Text PDFHighly efficient and thermally stable cyan-emitting ZnS/ZnO phosphors for full-visible-spectrum LED lighting.
RSC Adv
January 2025
Faculty of Materials Science and Engineering, Phenikaa University Yen Nghia, Ha-Dong District Hanoi 10000 Vietnam
Near-ultraviolet (NUV)-pumped white light-emitting-diodes (WLEDs) often suffer from poor color rendering in the 480-520 nm range, highlighting the need for an efficient cyan phosphor with strong absorption at 370-420 nm. This study presents the successful synthesis of cyan-emitting ZnS/ZnO phosphors using a high-energy planetary ball milling method followed by post-annealing. The fabricated phosphors, with particle sizes ranging from 1 to 3 μm, exhibit strong cyan emission with CIE chromaticity coordinates of (0.
View Article and Find Full Text PDFWant 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!