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Nanotechnology ; 27(42): 425401, 2016 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-27632684


In this work, we demonstrate homogeneously distributed In0.3Ga0.7N/GaN quantum disks (QDs), with an average diameter below 10 nm and a high density of 2.1 × 10(11) cm(-2), embedded in 20 nm tall nanopillars. The scalable top-down fabrication process involves the use of self-assembled ferritin bio-templates as the etch mask, spin coated on top of a strained In0.3Ga0.7N/GaN single quantum well (SQW) structure, followed by a neutral beam etch (NBE) method. The small dimensions of the iron cores inside ferritin and nearly damage-free process enabled by the NBE jointly contribute to the observation of photoluminescence (PL) from strain-relaxed In0.3Ga0.7N/GaN QDs at 6 K. The large blueshift of the peak wavelength by over 70 nm manifests a strong reduction of the quantum-confined Stark effect (QCSE) within the QD structure, which also agrees well with the theoretical prediction using a 3D Schrödinger equation solver. The current results hence pave the way towards the realization of large-scale III-N quantum structures using the combination of bio-templates and NBE, which is vital for the development of next-generation lighting and communication devices.

Sci Rep ; 5: 9371, 2015 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-25792119


Quantum dots photonic devices based on the III-V compound semiconductor technology offer low power consumption, temperature stability, and high-speed modulation. We fabricated GaAs nanodisks (NDs) of sub-20-nm diameters by a top-down process using a biotemplate and neutral beam etching (NBE). The GaAs NDs were embedded in an AlGaAs barrier regrown by metalorganic vapor phase epitaxy (MOVPE). The temperature dependence of photoluminescence emission energies and the transient behavior were strongly affected by the quantum confinement effects of the embedded NDs. Therefore, the quantum levels of the NDs may be tuned by controlling their dimensions. We combined NBE and MOVPE in a high-throughput process compatible with industrial production systems to produce GaAs NDs with tunable optical characteristics. ND light emitting diode exhibited a narrow spectral width of 38 nm of high-intensity emission as a result of small deviation of ND sizes and superior crystallographic quality of the etched GaAs/AlGaAs layer.

Nanotechnology ; 24(28): 285301, 2013 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-23787817


We successfully fabricated defect-free, distributed and sub-20-nm GaAs quantum dots (named GaAs nanodisks (NDs)) by using a novel top-down technique that combines a new bio-template (PEGylated ferritin) and defect-free neutral beam etching (NBE). Greater flexibility was achieved when engineering the quantum levels of ND structures resulted in greater flexibility than that for a conventional quantum dot structure because structures enabled independent control of thickness and diameter parameters. The ND height was controlled by adjusting the deposition thickness, while the ND diameter was controlled by adjusting the hydrogen-radical treatment conditions prior to NBE. Photoluminescence emission due to carrier recombination between the ground states of GaAs NDs was observed, which showed that the emission energy shift depended on the ND diameters. Quantum level engineering due to both diameter and thickness was verified from the good agreement between the PL emission energy and the calculated quantum confinement energy.

Arsenicais/química , Gálio/química , Nanoestruturas/química , Nanotecnologia/métodos , Pontos Quânticos , Biotecnologia/métodos , Ferritinas/química , Microscopia Eletrônica de Varredura , Nanoestruturas/ultraestrutura , Tamanho da Partícula , Polietilenoglicóis/química
Opt Express ; 21(6): 6910-8, 2013 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-23546074


Highly efficient, low-loss, and compact InP/InGaAsP polarization converter based on a half-ridge waveguide structure is fabricated and demonstrated experimentally. The device is fabricated by a simple self-aligned process and integrated with a ridge InP waveguide. Using a 150-µm-long device, we obtain the mode conversion of more than 96% and the on-chip loss of less than 1.0 dB over the broad wavelength range from 1510 to 1575 nm. The experimental results are explained quantitatively using the full-vector eigenmode calculation, which also reveals large fabrication tolerance of the demonstrated device.

Gálio/química , Índio/química , Fosfinas/química , Semicondutores , Ressonância de Plasmônio de Superfície/instrumentação , Desenho de Equipamento , Análise de Falha de Equipamento , Fótons , Integração de Sistemas
Opt Express ; 20(27): 28734-41, 2012 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-23263111


A strictly non-blocking 8 × 8 switch for high-speed WDM optical interconnection is realized on InP by using the phased-array scheme for the first time. The matrix switch architecture consists of over 200 functional devices such as star couplers, phase-shifters and so on without any waveguide cross-section. We demonstrate ultra-broad optical bandwidth covering the entire C-band through several Input/Output ports combination with extinction ratio performance of more than 20dB. Also, nanoseconds reconfiguration time was successfully achieved by dynamic switching experiment. Error-free transmission was verified for 40-Gbps (10-Gbps × 4ch) WDM signal.

Redes de Comunicação de Computadores/instrumentação , Índio/química , Dispositivos Ópticos , Fosfinas/química , Processamento de Sinais Assistido por Computador/instrumentação , Telecomunicações/instrumentação , Desenho de Equipamento , Análise de Falha de Equipamento