摘要：本研究計畫主題為以有機金屬氣相沉積之選擇性生長法來生長氮化銦鎵∕氮化鎵奈米材料結構，並製作奈米光學結構來達成高效率固態照明及太陽能電池之應用。此計畫包括三個長晶的課題、一個奈米光學結構之設計與製作課題、一個奈米光學量測技術發展及兩個應用主題。長晶方面，我們將從事：選擇性生長氮化銦鎵∕氮化鎵量子點及奈米柱以獲得易於控制之高效率且可達紅光波長之發光材料。同時，我們也將生長氮化銦及高銦氮化銦鎵以為太陽能電池之應用。在奈米光學結構上，我們將設計並製作於寬能隙氮化物發光二極體上之表面電漿波晶體及光子晶體來提昇發光二極體之發光及取光效率。在奈米光學量測上，我們將結合奈米尺寸螢光技術及飛秒時域螢光技術（含激發探測光譜術）來探討奈米結構內之超快載子動態及發光機制。至於在應用上，我們一方面將藉上述奈米技術來製作無螢光粉、單片全半導體之高效率白光發光二極體，作為固態照明及液晶顯示背光源，另一方面將製作基本型態之多接面太陽能電池及相關電子元件，以展示高銦氮化銦鎵應用於太陽能電池之可行性。為了上述研究，我們結合了六位不同專長之教授共同努力，也和國內外共六個研究團隊合作。
Abstract: The research theme of this proposal is the MOCVD selective-growth of InGaN/GaN nanostructures and the fabrication of nano-photonics structures for efficient solid-state lighting and solar cell applications. Basically, the project includes the developments of three MOCVD crystal-growth issues, one nano-photonics design and fabrication topic, one nano-photonics characterization technique, and two applications. In crystal growth, selective growths of InGaN/GaN quantum dots and nano-columns, and the growth of InN and indium-rich InGaN are the three challenging issues. Regarding the nano-photonics, we will design and fabricate surface plasmonic crystals and photonics crystals for enhancing photon emission and light extraction such that the external quantum efficiency of a light-emitting diode (LED) can be increased. To fully understand the material nanostructures and nano-photonics properties, we will combine the techniques of nano-photoluminescence and femtosecond time-resolved spectroscopy (including the pump-probe technique) for nano-optical characterization. The two major applications, including white-light generation and solar cell, will be developed. In developing the solar cell application, related electronics devices will also be designed and fabricated. In the selective growth of InGaN/GaN quantum dots and nano-columns, the first challenge is the process of nano-patterning on GaN templates. We propose to use the technique of anodized aluminum oxide for nano-scale patterning. As for InN and indium-rich InGaN, at the moment, most high-quality samples are grown with MBE. More efforts are needed for optimizing the growth conditions of MOCVD. In such efforts, p-type InGaN is a key issue for fabricating solar cells and other optoelectronics and electronics devices. Surface plasmonic and photonic crystals have been the issues of great interest for fundamental physics study and practical applications. Among many potential applications, they have proved useful for light extraction and emission enhancement in an LED. Although many reports have been found in literature about such an application, breakthrough improvements are still quite rare, particularly in the nitride-based LEDs. Spectroscopy measurements can provide us with the information of carrier dynamics, which gives us clues about the photon emission mechanisms. To this goal, in the spectroscopic measurements, we need to combine the nano-probe techniques for spatial resolution and the femtosecond technology for temporal resolution. Besides the traditional micro-photoluminescence (PL) techniques, we will use a novel method, based on a polished fiber as a solid immersion lens, for nano-scale PL measurement. We will also combine the near-field optics technique with time-resolved PL and pump-probe spectroscopy setups for monitoring the ultrafast carrier dynamics in the nano-scale. In particular, we will investigate the carrier dynamics when the carriers couple with surface plasmons or photonic crystal modes. Such information will help us in understanding the coupling process and hence in using such a process for LED radiation enhancement. The ultimate goals of the proposed research are the fabrications of practical devices, including white-light LEDs and solar cell (and related electronics). For the proposed research above, we organize the expertise of six faculty members to perform the team work.
