White-light Emitted InGaN Nanorods Grown on Pyramided Si Substrate

• Main Authors: Nien-TingTsai, 蔡念庭
• Other Authors: Chung-Lin Wu
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/70799793370194978645

碩士 === 國立成功大學 === 物理學系 === 104 === In this study, InGaN nanorods were grown on pyramided Si substrate by plasma-assisted molecular beam epitaxy system (PA-MBE). We have grown white-light emitting InGaN nanorods on pyramid Si substrate with single flux ratio, thus causing different In and Ga contents and different emission colors on each face of pyramid Si substrate. From SEM images, the different morphologies of the nanorods are revealed on each face of pyramid Si substrate. When In flux and Ga flux impinges vertically on pyramid, the InGaN nanorods show large rod diameter. However, when In flux and Ga flux impinges with grazing incidence on pyramid result in nanorods with small diameter. The length of the nanorods is about 1 μm. In addition, the direction of N flux enables to control the growth direction of InGaN nanorods on pyramid substrate, which we obviously found nanorods to tilt toward the top of pyramid. PL spectrum measurement results show that the white light emission has been achieved successfully by InGaN nanorods, and the spectrum exhibits a continuous emission range. We have confirmed that each face of pyramid substrate has different composition and different light emission by using spatial resolved catholuminescence (CL) and electron energy loss spectroscopy (EDS) measurements. Finally, we apply the mechanical force on InGaN nanorods, and PL spectrum shows the emission peaks with blue shift of 7 nm due to the photo-piezoelectric effect of III-nitride semiconductors.