Ping-Hsiu Wu

National Taiwan University

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Trends

Author Order

Document Type

Co-Authors

C. C. Yang

University of Science and Technology of China

Yu-Cheng Su

Beijing Institute of Technology

Yi-Chiao Hsu

National Taiwan University

Sheng-Yang Kuo

National Taiwan University

Yang Kuo

National Taiwan University

Shaobo Yang

National Taiwan University

Yangyi Huang

Eye & ENT Hospital of Fudan University

Yean‐Woei Kiang

National Taiwan University

Yu‐Wei Lin

National Taiwan University

T. Y. Huang

National Taiwan University

Cooperative Institutions

National Taiwan University

National Yang Ming Chiao Tung University

National Chung Hsing University

Industrial Technology Research Institute

ITRI International

National Taipei University

National Tsing Hua University

University of Illinois Urbana-Champaign

National Chi Nan University

Institute of Biological Chemistry, Academia Sinica

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Field

Surface Plasmon Resonance-Induced Diffusion-Limited Aggregation in the Formation of Ag/AgO_x Nanonetworks as Broad-Spectrum Transparent Conductors

ACS Applied Nano Materials (2020)

Yi-Chiao Hsu Chia-Chun Ni Yu-Cheng Su Ping-Hsiu Wu Jiawei Chen

Based on the generation and transportation of hot electrons and the diffusion-limited aggregation of Ag+ ions induced by the surface plasmon resonance of surface Ag nanoparticles (NPs) with ambient moisture, we develop a new mechanism for fabricating a surface Ag nanonetwork (NNW) structure on a slightly conductive template through Ag NP reorganization and AgOx formation. Such an extended NNW structure consists of distributed Ag NPs covered and connected by AgOx to form a highly transparent conductive network. Its sheet resistance is as low as ∼140 Ω/square while its transmittance lies between 80 and 90%. The process of diffusion-limited aggregation is regulated by electrostatic induction between diffuse Ag+ ions in a thin surface water layer condensed from moisture and the sharp tips of an NNW structure during its formation. Oxygen atoms can be dissociated from AgOx when a post-thermal treatment at a temperature higher than 412 °C is applied, leaving behind an Ag thin layer, which still connects the remaining Ag NPs to form a different conductive network of ∼240 Ω/square in sheet resistance. Such an NNW structure can stand an elevated temperature up to ∼400 °C and is thermally stable. It can extend the transparent spectrum into ultraviolet and near-infrared ranges and can be applied to touch-panel displays, ultraviolet light-emitting diodes, and flexible optoelectronics devices.

Ultraviolet

10.1021/acsanm.0c02480

Cite

Citations (3)

Photon color conversion enhancement of colloidal quantum dots inserted into a subsurface laterally-extended GaN nano-porous structure in an InGaN/GaN quantum-well template

Optics Express (2023)

Chen-Hua Chen Sheng-Yang Kuo His-Yu Feng Zong-Han Li Shaobo Yang

To improve the color conversion performance, we study the nanoscale-cavity effects on the emission efficiency of a colloidal quantum dot (QD) and the Förster resonance energy transfer (FRET) from quantum well (QW) into QD in a GaN porous structure (PS). For this study, we insert green-emitting QD (GQD) and red-emitting QD (RQD) into the fabricated PSs in a GaN template and a blue-emitting QW template, and investigate the behaviors of the photoluminescence (PL) decay times and the intensity ratios of blue, green, and red lights. In the PS samples fabricated on the GaN template, we observe the efficiency enhancements of QD emission and the FRET from GQD into RQD, when compared with the samples of surface QDs, which is attributed to the nanoscale-cavity effect. In the PS samples fabricated on the QW template, the FRET from QW into QD is also enhanced. The enhanced FRET and QD emission efficiencies in a PS result in an improved color conversion performance. Because of the anisotropic PS in the sample surface plane, the polarization dependencies of QD emission and FRET are observed.

Indium gallium nitride

Quantum Efficiency

10.1364/oe.478250

Cite

Citations (8)

Hole mobility behavior in Al-gradient polarization-induced p-type AlGaN grown on GaN template

Applied Physics Letters (2022)

Chung-Chi Chen T. Y. Huang Yu‐Wei Lin Yu‐Ren Lin Ping-Hsiu Wu

A series of samples with their AlGaN layers of decreasing Al contents along the c-axis are grown on GaN templates with molecular beam epitaxy for producing polarization-induced p-type behaviors. By fixing the Al-gradient rate at 0.15%/nm and AlGaN layer thickness at 100 nm while changing the central Al content in those samples, we study the dependence of hole mobility on the central Al content. As the central Al content increases, hole mobility decreases monotonically with two different decreasing slopes in the two Al-content ranges divided at ∼40%. Tensile strain relaxation is observed when the Al content is higher than ∼40%, resulting in the increase in overall polarization gradient and, hence, hole concentration. Although the variation of the alloy scattering strength of hole in AlGaN can support the smaller decreasing slope of hole mobility in the Al-content range of >40%, other factors, such as piezoelectric scattering and bound charge distribution, may need to be considered for a complete interpretation. Compared with Mg-doped p-type AlGaN of 25% in an Al content, the polarization-induced p-type AlGaN can provide us with a higher hole mobility level at about the same hole concentration.

Electron Mobility

Wide-bandgap semiconductor

10.1063/5.0070599

Cite

Citations (6)

Improvement of p-Type AlGaN Conductivity with an Alternating Mg-Doped/Un-Doped AlGaN Layer Structure

Micromachines (2021)

Chi‐Chung Chen Yu‐Ren Lin Yu‐Wei Lin Yu-Cheng Su Chung-Chi Chen

Using molecular beam epitaxy, we prepared seven p-type AlGaN samples of ~25% in Al content, including six samples with Mg-doped/un-doped AlGaN alternating-layer structures of different layer-thickness combinations, for comparing their p-type performances. Lower sheet resistance and higher effective hole mobility are obtained in a layer-structured sample, when compared with the reference sample of uniform Mg doping. The improved p-type performance in a layer-structured sample is attributed to the diffusion of holes generated in an Mg-doped layer into the neighboring un-doped layers, in which hole mobility is significantly higher because of weak ionized impurity scattering. Among the layer-structured samples, that of 6/4 nm in Mg-doped/un-doped thickness results in the lowest sheet resistance (the highest effective hole mobility), which is 4.83 times lower (4.57 times higher) when compared with the sample of uniform doping. The effects of the Mg-doped/un-doped layer structure on p-type performance in AlGaN and GaN are compared.

10.3390/mi12070835

Cite

Citations (5)

Combined effects of surface plasmon coupling and Förster resonance energy transfer on the light color conversion behaviors of colloidal quantum dots on an InGaN/GaN quantum-well nanodisk structure

Nanotechnology (2020)

Yen‐Po Chen Chia-Chun Ni Ruei-Nan Wu Sheng-Yang Kuo Yu-Cheng Su

By forming nanodisk (ND) structures on a blue-emitting InGaN/GaN quantum-well (QW) template, the QWs become close to the red-emitting quantum dots (QDs) and Ag nanoparticles (NPs) attached onto the sidewalls of the NDs such that Förster resonance energy transfer (FRET) and surface plasmon (SP) coupling can occur to enhance the efficiency of blue-to-red color conversion. With a larger ND height, more QWs are exposed to open air on the sidewall for more QD/Ag NP attachment through QD self-assembly and Ag NP drop casting such that the FRET and SP coupling effects, and hence the color conversion efficiency can be enhanced. A stronger FRET process leads to a longer QD photoluminescence (PL) decay time and a shorter QW PL decay time. It is shown that SP coupling can enhance the FRET efficiency.

Quantum Efficiency

Resonant inductive coupling

10.1088/1361-6528/abd05e

Cite

Citations (19)

Spatial range of the plasmonic Dicke effect in an InGaN/GaN multiple quantum well structure

Nanotechnology (2020)

Wai Fong Tse Ruei-Nan Wu Cai-Chen Lu Yi-Chiao Hsu Yen‐Po Chen

The plasmonic Dicke effect means a cooperative emission mechanism of multiple light emitters when they are simultaneously coupled with the same surface plasmon (SP) mode of a metal nanostructure to achieve a higher collective emission efficiency. Here, we compare the enhancements of emission efficiency among a series of SP-coupled InGaN/GaN quantum-well (QW) structures of different QW period numbers to show an emission behavior consistent with the plasmonic Dicke effect. The relative enhancement of overall emission efficiency increases with QW period number until it reaches a critical value, beyond which the enhancement starts to decrease. This critical QW period number corresponds to the effective depth range of the plasmonic Dicke effect in a multiple-QW system. It also represents an optimized QW structure for maximizing the SP coupling effect. Internal quantum efficiency and time-resolved photoluminescence are measured for comparing the enhanced emission efficiencies of blue and green QW structures with different QW period numbers through SP coupling induced by surface Ag nanoparticles.

Quantum Efficiency

10.1088/1361-6528/ab87cc

Cite

Citations (7)