Browsing by Author "Lin, Hsiang-Ting"

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Circular Dichroism Control of Tungsten Diselenide (WSe2) Atomic Layers with Plasmonic Metamolecules
(2018-05-09)
Lin, Hsiang-Ting
;
Chang, Chiao-Yun
;
Cheng, Pi-Ju
;
Li, Ming-Yang
;
Cheng, Chia-Chin
Controlling circularly polarized (CP) states of light is critical to the development of functional devices for key and emerging applications such as display technology and quantum communication, and the compact circular polarization-tunable photon source is one critical element to realize the applications in the chip-scale integrated system. The atomic layers of transition metal dichalcogenides (TMDCs) exhibit intrinsic CP emissions and are potential chiroptical materials for ultrathin CP photon sources. In this work, we demonstrated CP photon sources of TMDCs with device thicknesses approximately 50 nm. CP photoluminescence from the atomic layers of tungsten diselenide (WSe2) was precisely controlled with chiral metamolecules (MMs), and the optical chirality of WSe2 was enhanced more than 4 times by integrating with the MMs. Both the enhanced and reversed circular dichroisms had been achieved. Through integrations of the novel gain material and plasmonic structure which are both low-dimensional, a compact device capable of efficiently manipulating emissions of CP photon was realized. These ultrathin devices are suitable for important applications such as the optical information technology and chip-scale biosensing.
Circular Polarized Emission of Tungsten Diselenide (WSe2) Atomic Layers with Plasmonic Metasurface
(2018-01-01)
Lin, Hsiang-Ting
;
Chang, Chiao-Yun
;
Cheng, Pi-Ju
;
Li, Ming-Yang
;
Cheng, Chia-Chin
A circularly polarized light source with ultrathin geometry were demonstrated by integrating the WSe2 atomic layers with plasmonic chiral metasurfaces. The intrinsic chiral emission of WSe2 was manipulated by chiral metasurfaces to achieve emission circular dichroism more than 25%.
Flexible Localized Surface Plasmon Resonance Sensor with Metal-Insulator-Metal Nanodisks on PDMS Substrate
(2018-08-07)
Chang, Chiao-Yun
;
Lin, Hsiang-Ting
;
Lai, Ming-Sheng
;
Shieh, Teng-Yi
;
Peng, Chien-Chung
The small sized, flexible, high-performed and bio-compatible sensing devices are the critical elements to realize the bio-related detection or on-site health monitoring systems. In this work, the flexible localized surface plasmon resonance (LSPR) bio-sensors were demonstrated by integrating the metal-insulator-metal (MIM) nanodisks with bio-compatible polydimethylsiloxane (PDMS) substrate. The different geometries of MIM nanodisk sensors were investigated and optimized to enhance the spatial overlap of the LSPR waves with the environment, which lead to a high sensitivity of 1500 nm/RIU. The omni-directional characteristics of LSPR resonances were beneficial for maintaining the device sensitivity stable under various bending curvatures. Furthermore, the flexible MIM nanodisk LSPR sensor was applied to detect A549 cancer cells in PBS+ solution. The absorption peak of the MIM-disk LSPR sensor obviously redshift to easily distinguish between the phosphate buffered saline (PBS+) solution with A549 cancer cells and without cells. Therefore, the flexible MIM nanodisk LSPR sensor is suitable to develop on-chip microfluidic biosensors for detection of cancer cells on nonplanar surfaces.
High Circular Polarized Nanolaser with Chiral Gammadion Metal Cavity
(2020-05-12)
Yu, Cheng-Li
;
Hsiao, Yu-Hao
;
Chang, Chiao-Yun
;
Cheng, Pi-Ju
;
Lin, Hsiang-Ting
We demonstrate a circularly polarized laser with the metal-gallium-nitride gammadion nanocavities. The ultraviolet lasing signal was observed with the high circular dichroism at room temperature under pulsed optical pump conditions. Without external magnetism which breaks the time-reversal symmetry to favor optical transitions of a chosen handedness, the coherent outputs of these chiral nanolasers show a dissymmetry factor as high as 1.1. The small footprint of these lasers are advantageous for applications related to circularly polarized photons in future integrated systems, in contrast to the bulky setup of linearly-polarized lasers and quarter-wave plates.
High Color Conversion Efficiency on Monolayer WSe2 Using Plasmonic Metasurface
(2019-01-01)
Chen, Cheng-Yuan
;
Lin, Chen-An
;
Lin, Hsiang-Ting
;
Chang, Chiao-Yun
;
Kuo, Hao-Chung
The atomic scale thickness transition metal dichalcogenides (TMDCs) material could be a potential role of miniature light emitting devices (LED). The high color conversion efficiency between CdSe quantum dot (QD) and monolayer tungsten diselenide (WSe2) with Ag NDs metasurface could enhance the light emission of WSe2. The emission enhancement presented the color conversion due to its absorption spectrum of Ag ND. It had the most ideal overlap with QDs and WSe2 simultaneously, which boosted all the effects that would happen in color conversion. In the future, utilizing plasmonic metasurface and combing the TMDCs emitting visible red light with the GaN-based LED and green QDs to helpfully achieve white light emitting device. (C) 2019 The Author(s)
Hybrid Composites of Quantum Dots, Monolayer WSe2, and Ag Nanodisks for White Light-Emitting Diodes
(2020-07-24)
Chang, Chiao-Yun
;
Yu, Cheng-Li
;
Lin, Chen-An
;
Lin, Hsiang-Ting
;
Lee, Andrew Boyi
We investigated hybrid zero-dimensional core-shell CdSe/ZnS quantum dot (QD)/two-dimensional monolayer WSe2 semiconductors with an Ag nanodisk (ND) for manipulating plasmonic-enhanced photoluminescence (PL) and color conversion efficiency. The absorption spectrum of the local surface plasmon resonance (LSPR) effectively overlaps with that of QDs or monolayer WSe2 to considerably enhance PL. The broad absorption spectrum of the LSPR simultaneously overlapped with the emission spectrum of QDs and the absorption spectrum of excitons in WSe2 to enhance the color conversion efficiency. The highest efficiency of color conversion from QDs to WSe2 with Ag ND was 53%. In the future, hybrid QD/transition metal dichalcogenide light emitters could be further integrated with GaN-based white light-emitting diodes to manipulate the color temperature and expand the color gamut to develop a miniature white light-emitting diode.
Large-Area and Strain-Reduced Two-Dimensional Molybdenum Disulfide Monolayer Emitters on a Three-Dimensional Substrate
(2019-07-24)
Chang, Chiao-Yun
;
Lin, Hsiang-Ting
;
Lai, Ming-Sheng
;
Yu, Cheng-Li
;
Wu, Chong-Rong
Atomically thin membranes of two-dimensional (2-D) transition-metal dichalcogenides (TMDCs) have distinct emission properties, which can be utilized for realizing ultrathin optoelectronic integrated systems in the future. Growing a large-area and strain-reduced monolayer 2-D material on a three-dimensional (3-D) substrate with microstructures or nanostructures is a crucial technique because the electronic band structure of TMDC atomic layers is strongly affected by the number of stacked layers and strain. In this study, a large-area and strain-reduced MoS2 monolayer was fabricated on a 3D substrate through a two-step growth procedure. The material characteristics and optical properties of monolayer TMDCs fabricated on the nonplanar substrate were examined. The growth of monolayer MoS2 on a cone-shaped sapphire substrate effectively reduced the tensile strain induced by the substrate by decreasing the thermal expansion mismatch between the 2-D material and the substrate. Monolayer MoS2 grown on the nonplanar substrate exhibited uniform strain reduction and luminescence intensity. The fabrication of monolayer MoS2 on a nonplanar substrate increased the light extraction efficiency. In the future, large-area and strain-reduced 2-D TMDC materials grown on a nonplanar substrate can be employed as novel light-emitting devices for applications in lighting, communication, and displays for the development of ultrathin optoelectronic integrated systems.
Optical Chirality Tunable and Reversable Plasmonic Chiral Metasurfaces on Flexible PDMS Substrate
(2019-01-01)
Lin, Hsiang-Ting
;
Hsu, Yao-Yu
;
Chang, Chiao-Yun
;
Shih, Min-Hsiung
;
光電工程學系
We demonstrated a flexible plasmonic chiral metasurface which realized optical chirality both tunable and reversable. The controllable circular dichroism from -25% to +30% was achieved in the same metasurface under different stretch situations. (c) 2019 The Author(s)
Photonic Crystal Circular Nanobeam Cavity Laser with Type-II GaSb/GaAs Quantum Rings as Gain Material
(2020-03-16)
Lin, Hsiang-Ting
;
Hsu, Kung-Shu
;
Chang, Chih-Chi
;
Lin, Wei-Hsun
;
Lin, Shih-Yen
The optical emission from type-II semiconductor nanostructures is influenced by the long carrier lifetime and can exhibit remarkable thermal stability. In this study, utilizing a high quality photonic crystal circular nanobeam cavity with a high quality factor and a sub-micrometer mode volume, we demonstrated an ultra-compact semiconductor laser with type-II gallium antimonide/gallium arsenide quantum rings (GaSb/GaAs QRs) as the gain medium. The lasing mode localized around the defect region of the nanobeam had a small modal volume and significant coupling with the photons emitted by QRs. It leads the remarkable shortening of carrier lifetime observed from the time-resolved photoluminescence (TRPL) and a high Purcell factor. Furthermore, a high characteristic temperature of 114K was observed from the device. The lasing performances indicated the type-II QRs laser is suitable for applications of photonic integrated circuit and bio-detection applications.
Strain-reduced and Photoluminescence Enhanced of MoS2 Emitters on Three-Dimensional Substrate
(2020-01-01)
Lee, Andrew Boyi
;
Chang, Chiao-Yun
;
Lin, Hsiang-Ting
;
Lai, Ming-Sheng
;
Yu, Cheng-Li
Two-dimensional (2D) atomic transition metal dichalcogenides (TMDCs) have distinct emission properties, which can be applied for ultrathin detectors and light-emitters in the future. In this study, strain and photoluminescence of MoS2 monolayer on a 3D substrate through a two-step growth procedure was analyzed. The structural of materials and those optical properties of monolayer TMDCs fabricated on the planar and nonplanar substrate were examined. Monolayer MoS2 grown on the nonplanar substrate exhibited uniform strain reduction and luminescence intensity. The fabrication of monolayer MoS2 on a nonplanar substrate increased the light extraction efficiency. In the future, strain-reduced 2D TMDC materials grown on a nonplanar substrate can be employed as novel light-emitting devices for applications in light-emitters, communication, and displays for ultrathin optoelectronic integrated systems.
Using Planar Hyperbolic Metamaterials to Enhance Spontaneous Emission in Two-dimensional Transition Metal Dichalcogenides
(2018-01-01)
Lin, Chen-An
;
Yu, Cheng-Li
;
Lin, Hsiang-Ting
;
Chang, Chiao-Yun
;
Kuo, Hao-Chung
We designed one-dimensional planar hyperbolic metamaterials (P-HMMs) which supported high k modes and had better coupling compared to multilayers HMMs. Therefore, spontaneous emission enhancement and the strong coupling between P-HMMs and 2D materials were achieved.