플라즈모닉 도파로의 독창적인 구조와 태양전지 응용을 위한 금속 나노구조
A study on novel plasmonic waveguide structures and metallic nanostructures for solar cell application
- 주제(키워드) plasmonic waveguide , metallic nanostructure , solar cell , surface plasmon polariton , grating
- 발행기관 아주대학교
- 발행년도 2011
- 학위수여년월 2011. 8
- 학위명 박사
- 학과 및 전공 일반대학원 전자공학과
- 실제URI http://www.dcollection.net/handler/ajou/000000011845
- 본문언어 영어
- 저작권 아주대학교 논문은 저작권에 의해 보호받습니다.
초록/요약
Surface plasmon polaritons (SPPs) guided at the interface between metal and dielectric medium have attracted a lot of interest due to strong confinement of energy well beyond the diffraction limit associated with conventional waveguide of only dielectric materials. In spite of the excellent optical property, SPP based applications have been severely limited because the oscillating electrons inside metal region cause considerable ohmic loss, thus resulting in trade-off limitation between field confinement and attenuation. In this dissertation, author presents several solutions to circumvent or mitigate the restriction by using unique guiding mechanisms: vertical metal stripe waveguide with asymmetric background media, hybrid plasmonic waveguide mixing the index-guiding effect by adding dielectric slab, and waveguide guided by plasmonic mode-gap effect. And author introduces and demonstrates existence of new SPP mode supported in V-shaped thin metal film waveguide, unlike previously reported studies. Especially the possibility for nonlinear applications is discussed in detail. To effectively use the outstanding characteristics of SPP, author also devises smart structures for amorphous silicon based solar cell. The suggested solar cell shows considerable enhancement of absorption efficiency independent of the incident angle and polarization. Most of investigations have been conducted by analytical and numerical simulations: the modal analysis of waveguides structures was performed using finite difference method (FDM) and finite element method (FEM) with the perfectly matched layer boundary condition, and solar cell performance analysis was performed by rigorous coupled wave analysis (RCWA).
more목차
Chapter 1: Introduction 1
1.1 Introduction to SPP waveguides 1
1.2 Overall Objectives 2
1.3 Outline 3
Reference 4
Chapter 2: Theoretical background of SPP waveguides 5
2.1 Optical properties of metal 5
2.2 Electromagnetic waves inside bulk metal 6
2.3 SPP mode at single interface 7
2.4 Two TM SPP modes in DMD structure 11
2.5 Two TM SPP and Conventional modes in MDM structure 13
2.6 Figure of merit for SPP waveguides 15
Reference 16
Chapter 3: Metal stripe based SPP waveguides for flexible optical wiring 17
3.1 Introduction 17
3.2 Straight asymmetric vertical metal stripe waveguide 18
3.3 Curved asymmetric vertical metal stripe waveguide 21
3.3.1 Radiation behaviors for small asymmetry 21
3.3.2 Radiation behaviors and applications for very large asymmetry 26
3.4 Index-guiding-assisted hybrid plasmonic waveguides 29
3.4.1 Theoretical analysis for bending properties 29
3.4.2 Experimental results and discussion 36
3.5 Discussion and Summary 39
Reference 40
Chapter 4: Plasmonic Mode-Gap LR-SPP waveguides 42
4.1 Introduction 42
4.2 Physical background of plasmonic mode-gap effect 44
4.3 PMG waveguide based on the Hetero-Metal 46
4.3.1 Propagation properties of straight PMG waveguide 46
4.3.2 Bending properties of curved PMG waveguide 52
4.4 PMG waveguide based on the Hetero-Dielectric 57
4.4.1 Propagation properties of straight PMG waveguide 57
4.4.2 Bending properties of curved PMG waveguide 61
4.5 Discussion and Summary 64
Reference 65
Chapter 5: Channel plasmon polartions in thin metal V-grooves 68
5.1 Introduction 68
5.2 Modal analysis using one-dimensional approach 70
5.3 Metal thickness dependence of LR-CPP and SR-CPP modes 73
5.4 Propagation characteristics of LR-CPP for various parameters 75
5.5 Radiation properties of LR-CPP in asymmetric environment 77
5.6 Discussion and Summary 81
Reference 82
Chapter 6: Ultrathin metal grating based thin film solar cell 84
6.1 Introduction 84
6.2 Light absorption in solar cell using metal film 85
6.2.1 Metal thickness dependence of absorption 85
6.2.2 Effect of loss in the silver layer 87
6.2.3 a-Si thickness and incident angle dependence of absorption 88
6.3 Solar cell using ultrathin metal grating 90
6.3.1 Ultrathin metal grating and polarization dependency 90
6.3.2 a-Si thickness dependence of absorption 96
6.3.3 Fill factor dependence of absorption 99
6.3.4 Period dependence of absorption 102
6.3.5 Incident angle dependence of absorption 105
6.3.6 Contribution to absorption by a-Si 108
6.4 Discussion and Summary 110
Reference 112
Chapter 7: Conclusion and Future Work 114
Author's Publications 116
