本文選題：升華法 + 氮化鎵納米線��； 參考：《南京郵電大學》2017年碩士論文

【摘要】：作為第三代優(yōu)良的新型半導體材料,GaN因其寬禁帶、抗輻射、化學性質(zhì)穩(wěn)定等特性廣泛應(yīng)用于光電元器件的研制。近年來,隨著GaN材料特性的深入研究,研究人員實驗中發(fā)現(xiàn)了不僅可以生長GaN薄膜,還可以生長GaN一維納米材料,因此受到了國內(nèi)外的廣泛關(guān)注。本課題采用自主設(shè)計的升華法生長系統(tǒng),主要包括兩個部分,即基于計算流體力學的數(shù)值模擬和實驗制備GaN納米線的研究。為了縮短升華法生長系統(tǒng)的設(shè)計周期和有效改善腔體結(jié)構(gòu)設(shè)計,主要從生長溫度、襯底相對基座的高度和基座相對反應(yīng)腔體的高度等方面進行了二維模型的數(shù)值模擬,通過模擬分析襯底表面Ga、NH3的摩爾濃度分布和GaN生長速率等來研究對生長GaN納米線的影響。通過計算模擬分析得出生長溫度為1050℃、襯底相對高度為6mm和基座相對高度為25mm的生長條件下,模擬生長GaN納米線的生長均勻性更好。另外在已經(jīng)優(yōu)化的生長條件下又探討了加入不同流量的載氣N2后數(shù)值模擬分析反應(yīng)腔體內(nèi)部的流場分布情況。采用升華法生長技術(shù),從NH3流量、生長時間、催化劑和緩沖層等方面進行實驗室制備GaN納米線,通過掃描電子顯微鏡(SEM)對實驗制備的GaN納米線進行形貌表征分析。通過對比樣品的SEM圖的形貌表征,發(fā)現(xiàn)石墨烯插層、NH3流量,反應(yīng)時間、有無催化劑和GaN緩沖層對GaN納米線的形貌有較大影響。在適當?shù)陌睔饬髁�、在無催化劑時,石墨烯上可以生長GaN納米線,納米線直徑約80nm,長度約10μm。在引入緩沖層和催化劑后,GaN納米線呈現(xiàn)趨向豎直排列的模式。研究結(jié)果表明,石墨烯、緩沖層和催化劑對GaN納米結(jié)構(gòu)的成核提供了基礎(chǔ),在一定條件下可以生長出優(yōu)化的納米線結(jié)構(gòu)。通過數(shù)值模擬和實驗制備,對改善生長系統(tǒng)腔體結(jié)構(gòu)和優(yōu)化生長工藝提供理論依據(jù),對實驗生長GaN納米陣列具有一定的指導意義。
[Abstract]:As a new kind of semiconductor material of the third generation, gan is widely used in the development of optoelectronic components because of its wide band gap, radiation resistance and chemical stability. In recent years, with the in-depth study of the properties of GaN materials, researchers have found that not only GaN thin films can be grown, but also one-dimensional GaN nanomaterials can be grown, so it has attracted wide attention at home and abroad. The self-designed sublimation growth system consists of two parts: numerical simulation based on computational fluid dynamics (CFD) and experimental preparation of GaN nanowires. In order to shorten the design period of sublimation growth system and improve the design of cavity structure effectively, the numerical simulation of two-dimensional model is carried out mainly from the aspects of growth temperature, the height of substrate relative to base and the height of base relative to reactive cavity, etc. The influence of GaN nanowires on the growth of GaN nanowires was studied by simulating the molar concentration distribution of GaH3 and the growth rate of GaN on the substrate surface. The simulated growth temperature is 1050 鈩，

本文編號：1933053