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

【摘要】：作為第三代優(yōu)良的新型半導(dǎo)體材料,GaN因其寬禁帶、抗輻射、化學(xué)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(lái),隨著GaN材料特性的深入研究,研究人員實(shí)驗(yàn)中發(fā)現(xiàn)了不僅可以生長(zhǎng)GaN薄膜,還可以生長(zhǎng)GaN一維納米材料,因此受到了國(guó)內(nèi)外的廣泛關(guān)注。本課題采用自主設(shè)計(jì)的升華法生長(zhǎng)系統(tǒng),主要包括兩個(gè)部分,即基于計(jì)算流體力學(xué)的數(shù)值模擬和實(shí)驗(yàn)制備GaN納米線的研究。為了縮短升華法生長(zhǎng)系統(tǒng)的設(shè)計(jì)周期和有效改善腔體結(jié)構(gòu)設(shè)計(jì),主要從生長(zhǎng)溫度、襯底相對(duì)基座的高度和基座相對(duì)反應(yīng)腔體的高度等方面進(jìn)行了二維模型的數(shù)值模擬,通過(guò)模擬分析襯底表面Ga、NH3的摩爾濃度分布和GaN生長(zhǎng)速率等來(lái)研究對(duì)生長(zhǎng)GaN納米線的影響。通過(guò)計(jì)算模擬分析得出生長(zhǎng)溫度為1050℃、襯底相對(duì)高度為6mm和基座相對(duì)高度為25mm的生長(zhǎng)條件下,模擬生長(zhǎng)GaN納米線的生長(zhǎng)均勻性更好。另外在已經(jīng)優(yōu)化的生長(zhǎng)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(chǎng)分布情況。采用升華法生長(zhǎng)技術(shù),從NH3流量、生長(zhǎng)時(shí)間、催化劑和緩沖層等方面進(jìn)行實(shí)驗(yàn)室制備GaN納米線,通過(guò)掃描電子顯微鏡(SEM)對(duì)實(shí)驗(yàn)制備的GaN納米線進(jìn)行形貌表征分析。通過(guò)對(duì)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(shí)間、有無(wú)催化劑和GaN緩沖層對(duì)GaN納米線的形貌有較大影響。在適當(dāng)?shù)陌睔饬髁俊⒃跓o(wú)催化劑時(shí),石墨烯上可以生長(zhǎng)GaN納米線,納米線直徑約80nm,長(zhǎng)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(duì)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(zhǎng)出優(yōu)化的納米線結(jié)構(gòu)。通過(guò)數(shù)值模擬和實(shí)驗(yàn)制備,對(duì)改善生長(zhǎng)系統(tǒng)腔體結(jié)構(gòu)和優(yōu)化生長(zhǎng)工藝提供理論依據(jù),對(duì)實(shí)驗(yàn)生長(zhǎng)GaN納米陣列具有一定的指導(dǎo)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(hào)：1933053