本文選題：硅基發(fā)光 + 碳氧化硅薄膜��； 參考：《太原理工大學(xué)》2017年碩士論文

【摘要】：近幾十年來,由于硅具有優(yōu)良的電學(xué)和機械等性能且在地球上儲量豐富,硅材料已被廣泛關(guān)注。但由于單晶硅是間接帶隙半導(dǎo)體,電子躍遷發(fā)出光子,需要吸收或發(fā)射一個聲子,這比電子直接躍遷發(fā)出光子幾率小得多,這使得單晶硅發(fā)光微弱。因此設(shè)計高效、穩(wěn)定的硅基發(fā)光材料是光電子技術(shù)中的關(guān)鍵問題。其中稀土摻雜硅基發(fā)光材料可以很好的改善硅基發(fā)光效率。因為稀土材料發(fā)光性能優(yōu)良,其f-f躍遷的電子能級豐富、光譜峰形尖銳、顏色純度高,且稀土發(fā)光受外界影響小。此外,+3價的稀土離子,每一電子層中都含有未成對的電子,躍遷時釋放光子,適合摻雜到發(fā)光材料中。因此,硅基薄膜中摻雜稀土材料是實現(xiàn)硅基發(fā)光的一條重要途徑。本文將稀土離子——鋱摻雜到母體材料SiC_xO_y薄膜中,通過改變薄膜中碳元素的含量以及對樣品進(jìn)行不同溫度的退火,從而實現(xiàn)鋱離子的最優(yōu)發(fā)光,并分析其發(fā)光機制。首先,研究母體材料SiC_xO_y薄膜中氧含量對薄膜發(fā)光的影響機制。采用高頻等離子體增強化學(xué)氣相沉積技術(shù)(VHF-PECVD)在250℃下制備一系列非晶SiC_xO_y薄膜。改變薄膜中氧組分的含量,氧組分的變化會影響SiC_xO_y薄膜發(fā)光性質(zhì)和結(jié)構(gòu)。通過光致發(fā)光光譜(PL)研究發(fā)現(xiàn),隨著薄膜中氧組分的增加,其發(fā)光峰位由橙紅光逐漸向藍(lán)光移動,肉眼可見較強的發(fā)射光。熒光瞬態(tài)譜分析表明,薄膜的光子壽命在納秒量級。綜合觀察薄膜的XPS、FTIR光譜以及Raman譜,對薄膜的相結(jié)構(gòu)和化學(xué)鍵合進(jìn)行表征,我們分析SiC_xO_y薄膜的可調(diào)光發(fā)射機制。之后,研究鋱摻雜SiC_xO_y薄膜中碳含量和退火溫度對鋱離子發(fā)光的影響機制。采用磁控濺射技術(shù)在250℃下制備一系列SiC_xO_y:Tb薄膜。因為薄膜中適量的碳可以促進(jìn)形成納米硅團(tuán)簇,納米硅團(tuán)簇可以作為激子介導(dǎo)激發(fā)鋱離子發(fā)光。因此,當(dāng)薄膜中的碳適量時,以納米硅團(tuán)簇激發(fā)鋱離子發(fā)光為主,鋱離子的綠色發(fā)光增強。然而繼續(xù)增加薄膜中的碳含量時,鋱離子的發(fā)光強度反而減弱。這是由于薄膜中碳含量再增加時,以氧缺陷激發(fā)鋱離子發(fā)光為主,但是納米硅團(tuán)簇激子激發(fā)效果強于氧缺陷激子激發(fā)效果。因此,當(dāng)氧缺陷激發(fā)為主時,鋱離子發(fā)光減弱。此外,通過不同退火溫度之后的SiC_xO_y:Tb薄膜,鋱離子的綠色發(fā)光均有增強。因此,碳含量和退火溫度對薄膜中鋱離子的發(fā)光均有較大的影響。本文對不同碳含量以及不同退火溫度的SiC_xO_y:Tb薄膜的微結(jié)構(gòu)進(jìn)行表征,分析了鋱離子發(fā)光增強機制且找到鋱離子最優(yōu)發(fā)光條件。
[Abstract]:In recent decades, silicon has attracted much attention because of its excellent electrical and mechanical properties and abundant reserves on the earth. However, since the single crystal silicon is an indirect band gap semiconductor, the electron transition emits photons, which requires the absorption or emission of a phonon, which is much less likely than the direct electron transition, which makes the single crystal silicon weak in luminescence. Therefore, the design of high-efficiency and stable silicon-based luminescent materials is a key problem in optoelectronic technology. Among them, rare earth doped Si-based luminescent materials can improve the Si-based luminescence efficiency. Because of the excellent luminescence properties of rare earth materials, the f-f transition has rich electronic energy levels, sharp spectral peaks, high color purity, and rare earth luminescence is less affected by the outside world. In addition, three valence rare earth ions, each of which contains unpaired electrons, release photons during transition and are suitable for doping into luminescent materials. Therefore, doping rare earth materials in Si-based films is an important way to realize Si-based luminescence. In this paper, rare earth ion -terbium is doped into the SiCxO _ y film. By changing the content of carbon in the film and annealing the sample at different temperatures, the optimum luminescence of terbium ion is realized and its luminescence mechanism is analyzed. Firstly, the effect of oxygen content on the luminescence of sic _ s _ XO _ y thin films is studied. A series of amorphous sic _ XO _ XO _ y thin films were prepared by high frequency plasma enhanced chemical vapor deposition (VHF-PECVD) at 250 鈩，

本文編號：2021040