scholarly journals Monolayer-Scale GaN/AlN Multiple Quantum Wells for High Power e-Beam Pumped UV-Emitters in the 240–270 nm Spectral Range

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2553
Author(s):  
Valentin Jmerik ◽  
Dmitrii Nechaev ◽  
Kseniya Orekhova ◽  
Nikita Prasolov ◽  
Vladimir Kozlovsky ◽  
...  
Keyword(s):  
Electron Beam ◽  
Quantum Wells ◽  
Spectral Range ◽  
Stark Effect ◽  
Electron Gun ◽  
Spiral Growth ◽  
Surface Topology ◽  
Multiple Quantum ◽  
Uv Emitters ◽  
A Current

Monolayer (ML)-scale GaN/AlN multiple quantum well (MQW) structures for electron-beam-pumped ultraviolet (UV) emitters are grown on c-sapphire substrates by using plasma-assisted molecular beam epitaxy under controllable metal-rich conditions, which provides the spiral growth of densely packed atomically smooth hillocks without metal droplets. These structures have ML-stepped terrace-like surface topology in the entire QW thickness range from 0.75–7 ML and absence of stress at the well thickness below 2 ML. Satisfactory quantum confinement and mitigating the quantum-confined Stark effect in the stress-free MQW structures enable one to achieve the relatively bright UV cathodoluminescence with a narrow-line (~15 nm) in the sub-250-nm spectral range. The structures with many QWs (up to 400) exhibit the output optical power of ~1 W at 240 nm, when pumped by a standard thermionic-cathode (LaB6) electron gun at an electron energy of 20 keV and a current of 65 mA. This power is increased up to 11.8 W at an average excitation energy of 5 µJ per pulse, generated by the electron gun with a ferroelectric plasma cathode at an electron-beam energy of 12.5 keV and a current of 450 mA.

scholarly journals Investigations on the Optical Properties of InGaN/GaN Multiple Quantum Wells with Varying GaN Cap Layer Thickness

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Xiaowei Wang ◽  
Feng Liang ◽  
Degang Zhao ◽  
Zongshun Liu ◽  
Jianjun Zhu ◽  
...  
Keyword(s):  
Optical Properties ◽  
Quantum Wells ◽  
Layer Thickness ◽  
Stark Effect ◽  
Chemical Vapor ◽  
Multiple Quantum ◽  
Three Samples ◽  
Measurement Results ◽  
Cap Layer ◽  
The Difference

Abstract Three InGaN/GaN MQWs samples with varying GaN cap layer thickness were grown by metalorganic chemical vapor deposition (MOCVD) to investigate the optical properties. We found that a thicker cap layer is more effective in preventing the evaporation of the In composition in the InGaN quantum well layer. Furthermore, the quantum-confined Stark effect (QCSE) is enhanced with increasing the thickness of GaN cap layer. In addition, compared with the electroluminescence measurement results, we focus on the difference of localization states and defects in three samples induced by various cap thickness to explain the anomalies in room temperature photoluminescence measurements. We found that too thin GaN cap layer will exacerbates the inhomogeneity of localization states in InGaN QW layer, and too thick GaN cap layer will generate more defects in GaN cap layer.

Quantum confined Stark effect in ZnCdSe/MgZnCdSe multiple quantum wells grown on InP substrates

1998 ◽  
Vol 184-185 ◽  
pp. 732-736 ◽  
Author(s):  
Takeshi Nagano ◽  
Ichirou Nomura ◽  
Masaru Haraguchi ◽  
Masayuki Arai ◽  
Hiroshi Hattori ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Stark Effect ◽  
Multiple Quantum Wells ◽  
Multiple Quantum ◽  
Quantum Confined Stark Effect ◽  
Quantum Confined ◽  
Inp Substrates

High-efficiency electron-beam-pumped sub-240-nm ultraviolet emitters based on ultra-thin GaN/AlN multiple quantum wells grown by plasma-assisted molecular-beam epitaxy on c-Al2O3

2018 ◽  
Vol 11 (9) ◽  
pp. 091003 ◽  
Author(s):  
Valentin N. Jmerik ◽  
Dmitrii V. Nechaev ◽  
Alexey A. Toropov ◽  
Evgenii A. Evropeitsev ◽  
Vladimir I. Kozlovsky ◽  
...  
Keyword(s):  
Electron Beam ◽  
Molecular Beam Epitaxy ◽  
Quantum Wells ◽  
Molecular Beam ◽  
High Efficiency ◽  
Multiple Quantum Wells ◽  
Multiple Quantum

scholarly journals Piezoelectric Level Splitting in GaInN/GaN Quantum Wells

1999 ◽  
Vol 4 (S1) ◽  
pp. 357-362
Author(s):  
C. Wetzel ◽  
T. Takeuchi ◽  
H. Amano ◽  
I. Akasaki
Keyword(s):  
Quantum Wells ◽  
Electric Fields ◽  
High Performance ◽  
Stark Effect ◽  
Electronic Band Structure ◽  
Multiple Quantum Well ◽  
Multiple Quantum ◽  
Large Set ◽  
Electronic Band ◽  
Level Splitting

Identification of the electronic band structure in AlInGaN heterostructures is the key issue in high performance light emitter and switching devices. In device-typical GaInN/GaN multiple quantum well samples in a large set of variable composition a clear correspondence of transitions in photo- and electroreflection, as well as photoluminescence is found. The effective band offset across the GaN/GaInN/GaN piezoelectric heterointerface is identified and electric fields from 0.23 - 0.90 MV/cm are directly derived. In the bias voltage dependence a level splitting within the well is observed accompanied by the quantum confined Stark effect. We furthermore find direct correspondence of luminescence bands with reflectance features. This indicates the dominating role of piezoelectric fields in the bandstructure of such typical strained layers.

scholarly journals Piezoelectric Level Splitting in GaInN/GaN Quantum Wells

1998 ◽  
Vol 537 ◽  
Author(s):  
C. Wetzel ◽  
T. Takeuchi ◽  
H. Amano ◽  
I. Akasaki
Keyword(s):  
Quantum Wells ◽  
Electric Fields ◽  
High Performance ◽  
Stark Effect ◽  
Electronic Band Structure ◽  
Multiple Quantum Well ◽  
Multiple Quantum ◽  
Large Set ◽  
Electronic Band ◽  
Level Splitting

AbstractIdentification of the electronic band structure in AlInGaN heterostructures is the key issue in high performance light emitter and switching devices. In device-typical GaInN/GaN multiple quantum well samples in a large set of variable composition a clear correspondence of transitions in photo- and electroreflection, as well as photoluminescence is found. The effective band offset across the GaN/GaInN/GaN piezoelectric heterointerface is identified and electric fields from 0.23 - 0.90 MV/cm are directly derived. In the bias voltage dependence a level splitting within the well is observed accompanied by the quantum confined Stark effect. We furthermore find direct correspondence of luminescence bands with reflectance features. This indicates the dominating role of piezoelectric fields in the bandstructure of such typical strained layers.

Comparison of 10 MeV electron beam radiation effect on InGaN/GaN and GaN/AlGaN multiple quantum wells

2019 ◽  
Vol 210 ◽  
pp. 169-174 ◽  
Author(s):  
Qingxuan Li ◽  
Bo Li ◽  
Lei Wang ◽  
Zhongming Zheng ◽  
Baoping Zhang ◽  
...  
Keyword(s):  
Electron Beam ◽  
Quantum Wells ◽  
Radiation Effect ◽  
Multiple Quantum Wells ◽  
Multiple Quantum ◽  
Beam Radiation ◽  
Electron Beam Radiation

scholarly journals Recent Progress on Ge/SiGe Quantum Well Optical Modulators, Detectors, and Emitters for Optical Interconnects

Photonics ◽  
2019 ◽  
Vol 6 (1) ◽  
pp. 24 ◽  
Author(s):  
Papichaya Chaisakul ◽  
Vladyslav Vakarin ◽  
Jacopo Frigerio ◽  
Daniel Chrastina ◽  
Giovanni Isella ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Electric Fields ◽  
Silicon Germanium ◽  
Optical Interconnects ◽  
Stark Effect ◽  
Extinction Ratio ◽  
Optical Loss ◽  
Multiple Quantum ◽  
Optical Modulators ◽  
Absorption Mechanism

Germanium/Silicon-Germanium (Ge/SiGe) multiple quantum wells receive great attention for the realization of Si-based optical modulators, photodetectors, and light emitters for short distance optical interconnects on Si chips. Ge quantum wells incorporated between SiGe barriers, allowing a strong electro-absorption mechanism of the quantum-confined Stark effect (QCSE) within telecommunication wavelengths. In this review, we respectively discuss the current state of knowledge and progress of developing optical modulators, photodetectors, and emitters based on Ge/SiGe quantum wells. Key performance parameters, including extinction ratio, optical loss, swing bias voltages, and electric fields, and modulation bandwidth for optical modulators, dark currents, and optical responsivities for photodetectors, and emission characteristics of the structures will be presented.

scholarly journals Tunable room-temperature spin-selective optical Stark effect in solution-processed layered halide perovskites

2016 ◽  
Vol 2 (6) ◽  
pp. e1600477 ◽  
Author(s):  
David Giovanni ◽  
Wee Kiang Chong ◽  
Herlina Arianita Dewi ◽  
Krishnamoorthy Thirumal ◽  
Ishita Neogi ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Room Temperature ◽  
Stark Effect ◽  
Cryogenic Cooling ◽  
Oscillator Strengths ◽  
Multiple Quantum ◽  
Solution Processed ◽  
Lattice Matching ◽  
Light Matter Interaction ◽  
Optical Stark Effect

Ultrafast spin manipulation for opto–spin logic applications requires material systems that have strong spin-selective light-matter interaction. Conventional inorganic semiconductor nanostructures [for example, epitaxial II to VI quantum dots and III to V multiple quantum wells (MQWs)] are considered forerunners but encounter challenges such as lattice matching and cryogenic cooling requirements. Two-dimensional halide perovskite semiconductors, combining intrinsic tunable MQW structures and large oscillator strengths with facile solution processability, can offer breakthroughs in this area. We demonstrate novel room-temperature, strong ultrafast spin-selective optical Stark effect in solution-processed (C6H4FC2H4NH3)2PbI4 perovskite thin films. Exciton spin states are selectively tuned by ~6.3 meV using circularly polarized optical pulses without any external photonic cavity (that is, corresponding to a Rabi energy of ~55 meV and equivalent to applying a 70 T magnetic field), which is much larger than any conventional system. The facile halide and organic replacement in these perovskites affords control of the dielectric confinement and thus presents a straightforward strategy for tuning light-matter coupling strength.

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