氮化鎵/氮化銦鎵奈米結構之光學特性研究

Optical Studies on InGaN/GaN Nanostructures

劉子綺(Tzu-Chi Liu)

指導教授 ： 楊志忠

國立臺灣大學/電機資訊學院/光電工程學研究所/碩士(2008年)

https://doi.org/10.6342/NTU.2008.02044

摘要

在本研究中，我們首先證實了經由控制流量磊晶的方法，即成長過程中週期性地開或關閉鎵原子的供給，而同時持續地供給氮原子，成長出來的a-plane氮化鎵於r-plane藍寶石基板具有較佳的光學特性。根據光激螢光頻譜量測的結果，經由控制流量磊晶方法成長的a-plane氮化鎵薄膜確實遇有較好的發光特性。此外，光學量測結果也顯示經由控制流量磊晶方法成長的樣品具有較多的應力被釋放。
接著，我們展示了使用預應變成長技術成長的綠光氮化銦鎵/氮化鎵量子井，藉由在成長高濃度銦發光量子井層前先成長一層銦濃度大約為7%的氮化銦鎵/氮化鎵量子井，使得發光量子井層的成長溫度可以提高30°C，在光激頻譜量測中仍維持發光波長為544nm。由光學之研究中發現，內部量子效應和室溫的光激螢光頻譜強度分別有167%與140%的提升。

關鍵字

氮化鎵 ； 氮化銦鎵 ； 光學特性

並列摘要

In this research, we first demonstrate superior optical quality of a-plane GaN grown on r-plane sapphire substrate based on the flow-rate modulation epitaxy (FME) technique, in which the Ga atom supply is alternatively switched on and off with continuous nitrogen supply. Based on the results of photoluminescence measurements, one can observe the better optical property of the FME-grown a-plane GaN thin film. Besides, it was shown that strain was more relaxed in the FME sample.
Then, we demonstrate the enhanced emission efficiency and reduced spectral shifts of a green InGaN/GaN quantum-well (QW) light-emitting diode epitaxial structure by using the prestrained growth technique. By adding a ~7 %-indium InGaN/GaN QW to the structure before the growth of designated emitting high-indium QWs, the growth temperature of the emitting QWs can be raised by 30 oC while keeping about the same emission wavelength around 544 nm in photoluminescence (PL). The internal quantum efficiency and room-temperature PL intensity are increased by ~167 and ~140 %, respectively.

並列關鍵字

GaN ； InGaN ； nanostructures

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