Study of the Polarization Effect in InAs Quantum Dots/GaAs Nanowires

Cheng, Feng; Li, Bang; Li, Luying; Wang, Xi; Shen, Shaoli; Liu, Weijie; He, Zheng; Jia, Shuangfeng; Yan, Xin; Zhang, Xia; Wang, Jianbo; Gao, Yuan

doi:10.1021/acs.jpcc.8b11425

Cited by 8 publications

(4 citation statements)

References 50 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The electrostatic potential of the InAs QD area is apparently negative, especially at the vertex region, indicating accumulation of negative charges at the dot apex. Those negative charges might originate from unintentional n-type doping during synthesis, which is also reported in former studies using similar growth method [13]. According to the EDS elemental analysis, obvious carbon signals are also detected at the QD region (figure S2), which supports the suggested n-type doping of InAs QDs.…”

Section: Resultssupporting

confidence: 84%

“…In a previous study, we report the polarization effect in a InAs QDs/GaAs NW hybrid system, which corresponds well with the enhanced PL property [13]. The applied metalorganic chemical vapor deposition (MOCVD) growth method allows the epitaxial growth of InAs QDs on the {112} faces of the GaAs NW, which would find applications in highperformance lasers, single-photon sources and high efficiency solar cells [14].…”

Section: Introductionsupporting

confidence: 63%

See 1 more Smart Citation

Study of nanometer-scale structures and electrostatic properties of InAs quantum dots decorating GaAs/AlAs core/shell nanowires

Cheng

et al. 2020

Nanotechnology

Self Cite

View full text Add to dashboard Cite

The configurations of core/shell nanowires (NWs) and quantum dots (QDs) decorating NWs have found great applications in forming optoelectronic devices thanks to their superior performances. The combination of the two configurations would expect to bring more benefits, however, the nanometer-scale electrostatic properties of the QD/buffer layer/NW heterostructures are still unrevealed. In this study, the InAs QDs decorating GaAs/AlAs core/ shell NWs are systemically studied both experimentally and theoretically. The layered atomic structures, chemical information, and anisotropic strain conditions are characterized by comprehensive transmission electron microscopy (TEM) techniques. Quantitative electron holography analyses show a large number of electrons accumulating in the InAs QD, especially at the dot apex, and charges of reversed signs and similar densities are observed to distribute at the sequential interfaces, leaving great amounts of holes in the NW core. Theoretical calculations including simulated heterostructural band structures, interfacial charge transfer, and chemical bonding analysis are in good accordance with the experimental results, and prove the important role of the AlAs buffer layer in adjusting the heterostructural band structure as well as forming stable InAs QDs on the NW surfaces. These results could be significant for achieving related optoelectronic devices with better stability and higher efficiency.

show abstract

Section: Resultssupporting

confidence: 84%

Section: Introductionsupporting

confidence: 63%

Study of nanometer-scale structures and electrostatic properties of InAs quantum dots decorating GaAs/AlAs core/shell nanowires

Cheng

et al. 2020

Nanotechnology

Self Cite

View full text Add to dashboard Cite

show abstract

“…[79] Finally, also the pulsed laser deposition (PLD) technique should be mentioned, as besides being a wellestablished technique for the production of various thin film materials, [79] it was recently proposed also for the fabrication of metal oxide NWs in high pressure processes using inert gas instead of reactive oxygen. [87][88][89][90] The NWs morphology and dimensions, aspect ratio and area density, as well as their ordering, can be tailored by the anodization process parameters (voltage) and the choice of template characteristics. The main advantage of this family of processes is the low temperature required for crystallization, which contributes to considerably reduce the cost and complexity of equipment.…”

Section: Synthesis Of Metal Oxide Nanowires and Nanorodsmentioning

confidence: 99%

Recent Developments and Perspectives for Memristive Devices Based on Metal Oxide Nanowires

Milano

Porro

Valov

et al. 2019

Adv Elect Materials

116

View full text Add to dashboard Cite

Memristive devices are considered one of the most promising candidates to overcome technological limitations for realizing next‐generation memories, logic applications, and neuromorphic systems in the modern nanoelectronics and information technology. Despite the continuous efforts, understanding the resistive switching mechanism underlying memristive/neuromorphic behavior still represents a challenge. Metal oxide nanowire‐based memristors appear suitable model systems for a deeper understanding of the involved physical/chemical phenomena due the possibility for localizing and investigating the switching mechanism. In practical aspects, nanowire‐based devices can be grown using a bottom‐up approach, thus being considered reliable candidates for going beyond the current scaling limitations of the top‐down approach by the standard lithography. In addition, taking into advantage of the high surface‐to‐volume ratio of these nanostructures, new device functionalities can be achieved by exploiting surface effects. In the literature, a variety of nanowire‐based devices such as single nanowires, nanowire arrays, and networks are reported to exhibit memristive behavior, explained by different switching mechanisms. This work provides a comparative review and a comprehensive analysis of device performances and physical phenomena responsible for memristive and neuromorphic behavior in such nanostructures. The analysis of the state‐of‐art of memristor devices based on nanowires and nanorods represent a milestone toward the development of nanowire‐based artificial neural networks.

show abstract

“…Recently, electron holography as a unique phase-obtaining technique has been successfully applied to the characterization of the electrostatic potentials, − electric fields, and charge distributions − across semiconductor heterostructures, owing to its high spatial resolution and sensitivity to variations in phase shifts . In the current case, through electron holographic characterization of the GaAs/AlGaAs SQW/NW heterostructure which forms a type-I band alignment (Figure c), the detailed charge distributions across the hetero-interfaces and the nanometer scale mechanism for the observed novel optoelectronic properties are clearly revealed.…”

Section: Resultsmentioning

confidence: 89%

Study of Charge Distributions and Electrical Properties in GaAs/AlGaAs Single Quantum Well/Nanowire Heterostructures

Cheng

et al. 2019

J. Phys. Chem. C

Self Cite

View full text Add to dashboard Cite

By embedding quantum wells (QWs) in semiconductor nanowires (NWs), the confined electronic states perpendicular to the NW axis as well as free movements along the NW axis can be simultaneously achieved. Among them, AlGaAs NWs are ideal candidates for radial two-dimensional GaAs QWs because of their nearly perfect lattice matching, negligible piezoelectric, and strain effects. A series of studies based on AlGaAs NWs with embedded QWs have revealed novel electronic states and outstanding properties. On the other hand, their electrical properties and underlying mechanism at the nanometer scale have less been reported. Herein, the electrical properties of GaAs QW/AlGaAs NW interfaces are quantitatively characterized via off-axis electron holography. Our results reveal that considerable electrons are confined in the GaAs QW, leaving massive holes distributing at the GaAs/AlGaAs hetero-interfaces. In addition, in combination with the first-principles calculations, the redistribution of charges causing band bending at GaAs/AlGaAs interfaces is calculated, which complies well with our experiment. The quantum confinement effect in this heterostructure due to the introduction of GaAs QW is also revealed, which causes the change of related band gap, leading to blue-shift in photoluminescence (PL) spectra. This work provides insight into the nanometer-scale electrical properties of III–V semiconductor NWs comprising QW, which may shed light on optimizing similar hybrid structures as optoelectronic devices in the future.

show abstract

Study of the Polarization Effect in InAs Quantum Dots/GaAs Nanowires

Cited by 8 publications

References 50 publications

Study of nanometer-scale structures and electrostatic properties of InAs quantum dots decorating GaAs/AlAs core/shell nanowires

Study of nanometer-scale structures and electrostatic properties of InAs quantum dots decorating GaAs/AlAs core/shell nanowires

Recent Developments and Perspectives for Memristive Devices Based on Metal Oxide Nanowires

Study of Charge Distributions and Electrical Properties in GaAs/AlGaAs Single Quantum Well/Nanowire Heterostructures

Contact Info

Product

Resources

About