Chee-Keong Tan

Chee-Keong Tan
Clarkson University · Department of Electrical & Computer Engineering

PhD in Electrical Engineering

About

66
Publications
5,622
Reads
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715
Citations
Citations since 2017
38 Research Items
449 Citations
2017201820192020202120222023020406080
2017201820192020202120222023020406080
2017201820192020202120222023020406080
2017201820192020202120222023020406080

Publications

Publications (66)
Conference Paper
The spontaneous emission characteristics of InGaN / dilute-As GaNAs interface quantum well for the visible spectral regime were calculated and analyzed, and the findings revealed the strong potential of implementing the dilute-anion IIINitride alloy as active region for high efficiency visible light emitter.
Article
The optical gain and spontaneous emission characteristics of low In-content AlInN-delta-GaN quantum wells (QWs) are analyzed for deep ultraviolet (UV) light emitting diodes (LEDs) and lasers. Our analysis shows a large increase in the dominant transverse electric (TE) polarized spontaneous emission rate and optical gain. The remarkable enhancements...
Article
The design of InGaN/dilute-As GaNAs interface quantum well (QW) leads to significant redshift in the transition wavelength with improvement in electron-hole wave function overlap and spontaneous emission rate as compared to that of the conventional In0.2Ga0.8N QW. By using self-consistent six-band k·p band formalism, the nitride active region consi...
Article
The band structure of dilute-As GaNAs alloy with the As composition range from 0% to 12.5% is studied by using First-Principle density-functional calculation. Our analysis shows that the dilute-As GaNAs alloy exhibits the direct band gap properties. The dilute-As GaNAs alloy shows a band gap range from 3.645 eV down to 2.232 eV with As content vary...
Article
The dilute-As InGaNAs-based quantum well (QW) active region and the corresponding large-overlap design is analyzed by using a self-consistent 6-band k∙p method. Our study evaluates the optical transition energy, ground state electron-hole wavefunction overlap, and optical gain characteristics of a dilute-As InGaNAs QW consisting of a 3.3 nm thick I...
Preprint
Full-text available
Vanadium dioxide (VO2) as a phase-change material controls the transferred heat during phase transition process between metal and insulator states. At temperature above 68C, the rutile structure VO2 keeps the heat out and increases the IR radiation reflectivity, while at the lower temperature the monoclinic structure VO2 acts as the transparent mat...
Article
Full-text available
Vanadium dioxide (VO2) as a phase-change material controls the transferred heat during phase transition process between metal and insulator states. At temperature above 68 C, the rutile structure VO2 keeps the heat out and increases the IR radiation reflectivity, while at the lower temperature the monoclinic structure VO2 acts as the transparent ma...
Conference Paper
The need for rapid, compact, and accurate biosensing capability has increased dramatically in recent times in biomedical and environmental applications. Optical biosensing is one of the most promising methods for virus and chemical substance detection. With analytes or substance binding to the ligands that are attached to the surface or nanoparticl...
Article
Efficient p-type doping of III-nitride materials is notoriously difficult due to their large bandgaps, intrinsic n-type doping, and the large ionization energy of acceptors. Specifically, aluminum-containing nitrides such as AlN and AlGaN have demonstrated low p-type conductivity, which increases device resistances and reduces carrier injection in...
Article
Wide-gap oxide materials including gallium oxide and aluminium oxide have been attracting much interest due to their tremendous potential for application in power devices. In this work, a new III-oxide...
Article
Gallium oxide has been attracting much interest due to its tremendous potential for power device application. The (BxGa1−x)2O3 ternary alloys of monoclinic and orthorhombic phases with the B-content covering the full composition were studied using first-principles density functional theory calculations. The effect of the B-content on the structural...
Article
Full-text available
Effective filtration of orbital angular momentum (OAM) modes is essential to achieve multiple-channel data transmission in an OAM fiber for telecommunication applications. The nature of helical-shaped OAM wave propagation possessing many topological charges implies the need for uniquely designed index-modulated filters to conform to its twisted pro...
Article
The dilute-As InyGa1 − yN1 − xAsx alloys are explored by performing first-principles density functional theory (DFT) calculations, where the In-content is varied from 0% up to 18.75% and the As-content is varied from 0% up to 3.13%. The obtained band structures indicate a direct bandgap semiconductor, whose electronic properties are modified signif...
Article
Full-text available
First-principles density functional theory is applied to investigate the electronic and structural properties of dilute-Se β-Ga2(O1−xSex)3 alloys with the Se-content ranging from 0% to 16.67%. The findings showed that the addition of Se has significant effect on the β-Ga2O3 alloy properties. The equilibrium volume and lattice parameters of β-Ga2(O1...
Article
UV ray detection near the earth surface has become urgent due to the serious effects of UV rays on human health, the environment and the biological evolution; therefore, the development of energy-saving UV photodetectors with high responsivity, specific detectivity, and sensitivity is urgently desired. Herein, we fabricated a lateral β-Ga2O3 Schott...
Article
Full-text available
The band structure of the dilute-As GaNAs material is explained by the hybridization of localized As-impurity states with the valance band structure of GaN. Our approach employs the use of Density Functional Theory (DFT) calculated band structures, along with experimental results, to determine the localized As-impurity energy level and coupling par...
Article
Full-text available
We report on the electronic properties of β-(InxGa1-x)2O3 alloys with different In-content up to 18.75% using density functional theory (DFT) calculations. The effect of In-content on the band structures as well as the crystal structures of β-(InxGa1-x)2O3 alloys is presented and discussed. Our analysis shows that β-(InxGa1-x)2O3 alloys exhibits in...
Article
Full-text available
The electronic properties of dilute-P AlN 1-x P x alloys are investigated by means of First-Principle Density Functional Theory (DFT) calculations, where the phosphorus (P) content is varied from 0% up to 6.25%. Band structure calculations indicate significant modifications of the electronic properties with the introduction of P-atoms, with the pos...
Article
Full-text available
An investigation on the optical properties of dilute-P GaN1−xPx alloys by First-Principle Density Functional Theory (DFT) methods is presented, for phosphorus (P) content varying from 0% up to 12.5%. Findings on the imaginary and real part of the dielectric function are analyzed and the results are compared with previously reported theoretical work...
Article
Full-text available
A novel III-Nitride digital alloy (DA) with ultra-broadband optical gain is proposed. Numerical analysis shows a 50-period InN/GaN DA yields minibands that are densely quantized by numerous confined states. Interband transitions between the conduction and valence minibands create ultra-broadband optical gain spectra with bandwidths up to ~1 μm that...
Article
Full-text available
A physically intuitive current injection efficiency model for a GaN:Eu quantum well (QW) has been developed to clarify the necessary means to achieve device quantum efficiency higher than the state-of-the-art GaN:Eu system for red light emission. The identification and analysis of limiting factors for high internal quantum efficiencies (IQE) are ac...
Article
Full-text available
The AlN/GaN digital alloy (DA) is a superlattice-like nanostructure formed by stacking ultra-thin (≤ 4 monolayers) AlN barriers and GaN wells periodically. Here we performed a comprehensive study on the electronics and optoelectronics properties of the AlN/GaN DA for mid-and deep-ultraviolet (UV) applications. Our numerical analysis indicates signi...
Article
Full-text available
Auger recombination in a semiconductor is a three-carrier process, wherein the energy from the recombination of an electron and hole pair promotes a third carrier to a higher energy state. In semiconductor quantum wells with increased carrier densities, the Auger recombination becomes an appreciable fraction of the total recombination rate and degr...
Article
Here, we reveal a remarkable (and surprising) physical property of GaN: it is extremely wear resistant. In fact, we measured the wear rate of GaN is approaching wear rates reported for diamond. Not only does GaN have an ultralow wear rate but also there are quite a few experimental factors that control the magnitude of its wear rate, further contri...
Article
A study on the electronic properties of the dilute-P GaNP alloy using First-Principle Density Functional Theory (DFT) calculations is presented. Our results indicate a band gap energy coverage from 3.645eV to 2.697eV, with P-content varying from 0% to 12.5% respectively. In addition, through line fitting of calculated and experimental data, a bowin...
Article
In this work, the amorphous Eu3+-doped TiO2 spheres were synthesized by low cost mixed-solvent method, while the anatase and rutile spheres can be obtained by annealing the as-synthesized amorphous TiO2 spheres at elevated temperatures. The optical properties of Eu3+-doped TiO2 spheres were also investigated, and strong red emission (centered at 61...
Article
The band structures of dilute-As AlNAs alloys with As composition ranging from 0% up to 12.5% are studied by using First-Principle Density Functional Theory (DFT) calculation. The energy band gap shows remarkable reduction from 6.19 eV to 3.87 eV with small amount of As content in the AlNAs alloy, which covers the deep ultraviolet (UV) spectral reg...
Article
The light extraction efficiency of thin-film flip-chip InGaN-based light-emitting diodes (LEDs) with TiO2 microlens arrays was calculated by employing finite-difference time-domain (FDTD) method. The microlens arrays formed by embedding hexagonal close packed TiO2 sphere arrays in polystyrene (PS) layer were placed on top of the InGaN LED to serve...
Conference Paper
The gain and spontaneous emission characteristics of AlInN quantum well were calculated and analyzed using 6-band k.p method, and the finding revealed the potential of employing AlInN alloy as active region for deep ultraviolet emitter.
Conference Paper
The paper presents the physics, materials, and devices for high-efficiency III-Nitride light-emitting diodes (LEDs) applicable for illumination and smart lighting. The fundamental concepts and breakthroughs for addressing the limitations in III-Nitride LEDs will be presented, and the future directions in laser based solid state lighting and smart l...
Conference Paper
First-principle analysis of the band structures for dilute-As AlN 1−x A sx semiconductor was performed, and the findings showed the direct bandgap properties of this alloy covering the deep ultraviolet spectral regime useful for new ultraviolet emitter.
Article
Full-text available
The evaluation of Auger recombination process for dilute-As GaNAs alloy is presented. Our analysis indicates the suppression of interband Auger recombination mechanism in dilute-As GaNAs alloy in the green spectral regime. The interband Auger coefficient in dilute-As GaNAs alloy is shown as two orders of magnitude lower than that of its correspondi...
Article
The 2014 Nobel prize in Physics was awarded for the development of blue-emitting InGaN-based light-emitting diodes (LEDs). In the last two decades, substantial progress has been made in the fields of visible LEDs driven by both materials and device innovations in InGaN based platforms. Extending this type of progress to the development of electrica...
Article
Full-text available
Density functional theory (DFT) calculations with the local density approximation (LDA) functional are employed to investigate the band alignment of dilute-As GaNAs alloys with respect to the GaN alloy. Conduction and valence band positions of dilute-As GaNAs alloy with respect to the GaN alloy on an absolute energy scale are determined from the co...
Conference Paper
The thin-film flip-chip (TFFC) light-emitting diodes (LEDs) are the state-of-the-art LED technology, which combined with phosphor materials to generate white light for general illumination and display technologies. However, the efficiency needs to be further improved and the manufacture cost needs to be reduced in order to widely adopt the GaN-base...
Conference Paper
The thin-film flip-chip (TFFC) light-emitting diodes (LEDs) are the state-of-the-art LED technology. Various approaches to enhance the light extraction efficiency have been implemented on TFFC GaN LED. Low-cost and practical method for enhancing the light extraction efficiency in TFFC GaN LED is important for the general illumination market. Recent...
Conference Paper
GaN-based white light-emitting diode (LED) is the technology of choice for solid state lighting. Commercialized white LED was obtained by coating an InGaN blue LED with a yellow-emitting phosphors (YAG: Ce3+), which has led to its wide use in the various outdoor lighting applications. Despite their wide applications and high luminous efficacy, the...
Conference Paper
Generation of hydrogen with low cost method is important for providing the clean energy in various energy consuming applications. One of the methods is to use TiO2 material in photoelectrochemical cell (PEC), however, the solar-to-hydrogen conversion efficiency is low due to the low solar energy absorption. Finding the suitable catalyst materials w...
Conference Paper
The importance of having low-cost and practical technology for enabling improved light extraction efficiency in GaN-based light-emitting diodes (LEDs) is key for the practical implementation of this technology for general illumination market. The use of surface roughness, photonic crystal, and nanopyramid approaches have been reported. The thin-fil...
Conference Paper
The paper will review the physics and key advances in the fields of III-Nitride light-emitting diodes, specifically on approaches to address internal quantum efficiency, extraction efficiency, and efficiency droop in emitters.
Article
The electrical and optical characteristics of InGaN quantum-well light-emitting diodes with large-bandgap AlGaInN thin barriers were analyzed with the consideration of carrier transport effect for efficiency droop suppression. The lattice-matched AlGaInN quaternary alloys with different compositions, thicknesses, and positions were employed as thin...
Conference Paper
The characteristics of InGaN quantum wells light-emitting diodes with thin large bandgap AlGaInN barriers were analyzed with taking into account the carrier transport effect, which resulted in efficiency-droop suppression.
Conference Paper
First-principle analysis of the band structure for dilute-As GaN1-xAsx semiconductor was carried out, and the finding showed the direct bandgap properties of this alloy covering the entire visible spectral regime applicable for new visible emitters.
Conference Paper
The review of the approaches to achieve high efficiency III-Nitride based visible and UV light-emitting diodes will be presented. The engineering from nanoscale, microscale, and macroscale in devices will be elaborated for high efficiency devices.

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Projects (2)
Project
wear mechanism, tribochemistry, surface states, III-Nitrides