Abstract
摘要：基於本研究團隊過去幾年來所建立獨特的氮化鎵奈米柱生長技術及相關研究成果，本計畫中我們擬以實驗及理論方法進一步探討數個關鍵課題，包括(1)利用圓形或橢圓形輪廓的多節奈米柱發光二極體陣列來實現免用螢光粉的白光發光元件、(2)理論探討利用有機金屬氣相沉積脈衝生長技術的奈米柱生長機制、(3)以whispering-gallery共振及光子晶體能隙特性來製作奈米共振腔發光二極體。為了拓寬奈米柱陣列整體的發光頻譜，我們將利用新穎生長技術改善在奈米柱側壁的電流擴散效果，並提高側壁氮化銦鎵/氮化鎵量子井的銦含量。奈米柱生長機制的理論研究包括奈米柱截面大小與高度和生長條件之關係、奈米柱截面漸變型態演化和脈衝生長條件的關係、多節奈米柱內節與節之間轉移的過程、側壁量子井在不同高度及不同節間結構與銦含量之變化。為了製作奈米共振腔發光二極體，我們首先探討單根奈米柱內的whispering-gallery共振行為，然後研究奈米柱陣列的耦合whispering-gallery共振特性。隨後，我們將設計並製作具有光子晶體能隙特性的奈米柱陣列並和whispering-gallery共振與表面電漿子耦合效果結合來探討整個共振效果，表面電漿子耦合效果係由在奈米柱側壁上製作銀奈米顆粒來產生。
本研究計畫最終目標為提升固態照明技術，固態照明應用係全球節能減碳的重要工作，目前我國也在這方面受到國際壓力，本計畫有助於解決這個社會問題。另外發光二極體係我國重要產業，本計畫有助於這部分的經濟發展。其次本計畫中我們將探討一些物理及技術課題，將貢獻於學術發展。
Abstract: Based on the unique core-shell GaN nanorod (NR) growth technique built by this research team and their related research accomplishments in the past few years, several key issues will be further studied experimentally and theoretically in this project. They include (1) implementation of phosphor-free white-light generation in a multi-section NR light-emitting diode (LED) array with circular or elliptical cross-sectional circumscription in individual NRs, (2) theoretical investigations of GaN NR growth mechanisms based on the pulsed growth technique with metalorganic chemical vapor deposition and related experimental verifications, and (3) fabrication of nano-cavity LEDs with whispering-gallery resonance (WGR) and photonic bandgap behaviors. To broaden the overall emission spectrum of an NR array for implementing white-light generation, current spreading on NR sidewalls will be improved and indium incorporation in growing sidewall InGaN/GaN quantum wells (QWs) will be enhanced based on proposed novel growth techniques. The theoretical studies on NR growth mechanisms include the dependencies of NR cross-sectional size and height on growth condition, the dependence of the tapering morphology evolution of an NR on the pulsed growth parameters, the transition process from one uniform section into another, and the variations of well width and indium content in the QWs at different sidewall heights or in different uniform sections. For fabricating nano-cavity NR LED devices, the WGR behaviors in a single NR will be investigated first, followed by the study on the coupled WGR characteristics in an NR array. An NR array to form a photonic bandgap will be designed and fabricated for combining with the WGR behaviors and the surface plasmon coupling effects, which are induced by forming Ag nanoparticles on NR sidewalls, to study the overall resonance properties in such a nano-cavity LED structure.
The accomplishments of this project can help in promoting the technology of solid state lighting, which is a key issue for saving energy and reducing carbon dioxide on the earth. Currently, Taiwan is under a lot of international pressures for contributing to carbon dioxide reduction. This project can help in this social issue. Also, LED is an important high-tech industry in Taiwan. This project aims at the development of novel LED techniques and hence can help in this economical issue. Meanwhile, physical and technical subjects are to be explored in this project for promoting the academic development.
Keyword(s)
氮化鎵奈米柱
多節奈米柱發光二極體
脈衝成長機制
whispering-gallery共振
光子晶體能隙
GaN nanorod
multi-section nanorod light-emitting diode
pulsed growth mechanism
whispering-gallery resonance
photonic bandgap
