發(fā)布時(shí)間：2018-06-06 01:12

  本文選題：PECVD + nc-Si:H薄膜　； 參考：《浙江師范大學(xué)》2015年碩士論文

【摘要】：氫化納米晶硅(hydrogenated nanocrystalline silicon, nc-Si:H)薄膜是硅的納米晶粒鑲嵌在氫化非晶硅(hydrogenated amorphous silicon, a-Si:H)網(wǎng)絡(luò)里的一種硅納米結(jié)構(gòu)材料。它具有高電導(dǎo)率、寬帶隙、高吸收系數(shù)、光致發(fā)光等光電特性,已經(jīng)引起了學(xué)術(shù)界的廣泛關(guān)注和研究。一方面,nc-Si:H薄膜材料具有量子限制效應(yīng),因此可以通過(guò)控制薄膜中的晶粒尺寸等來(lái)調(diào)節(jié)薄膜的帶隙,以應(yīng)用于對(duì)不同波段的光的吸收。另一方面,nc-Si:H薄膜材料具有良好的光照穩(wěn)定性,無(wú)明顯的光致衰退效應(yīng),有望應(yīng)用于薄膜太陽(yáng)能電池工業(yè)化生產(chǎn)中。然而,nc-Si:H薄膜材料的結(jié)構(gòu)、電學(xué)等性質(zhì)強(qiáng)烈地依賴于其所制備的工藝參數(shù)。因此,本文利用等離子體增強(qiáng)化學(xué)氣相沉積(plasma-enhanced chemical vapor deposition, PECVD)法系統(tǒng)地研究了工藝參數(shù)(射頻功率、氫稀釋比、沉積溫度、磷或硼摻雜比)對(duì)本征及摻雜nc-Si:H薄膜晶化特性、電導(dǎo)率及生長(zhǎng)速率的影響。研究結(jié)果表明：(1)在一定范圍內(nèi),隨著射頻功率的增加,本征和摻雜nc-Si:H薄膜的晶化率、晶粒大小、沉積速率及電導(dǎo)率都在提高,但是過(guò)高的射頻功率會(huì)使得薄膜表面被大量的原子轟擊,導(dǎo)電性下降；(2)提高氫稀釋比是制備nc-Si:H薄膜最有效的方法。隨著氫稀釋比的增加,薄膜逐漸由非晶轉(zhuǎn)變?yōu)榧{米晶,而且氫稀釋比越大,晶化程度越高,但是會(huì)顯著降低薄膜的沉積速率；(3)在一定范圍內(nèi),提高沉積溫度可以提高n型和本征nc-Si:H薄膜的晶化程度和導(dǎo)電性,但是對(duì)p型nc-Si:H薄膜剛好相反,主要是因?yàn)閾脚鸬膎c-Si:H薄膜在高溫下更容易脫氫所致；(4)隨著磷或硼摻雜比的增加,薄膜晶化程度在降低,而沉積速率在增加。在一定范圍內(nèi),磷摻雜比越高,薄膜導(dǎo)電性越好。而硼摻雜比越高,薄膜導(dǎo)電性越差,且超過(guò)0.5%的硼摻雜比就會(huì)導(dǎo)致薄膜的非晶化。最后,選取最優(yōu)的工藝參數(shù),初步探索了nc-Si:H薄膜在p-i-n型薄膜電池上的應(yīng)用,獲得的最高光電轉(zhuǎn)換效率為4.97%。金屬誘導(dǎo)晶化(metal induced crystallization, AIC)也是制備納米晶硅或硅納米線(SiNWs)的常見方法之一,本文利用PECVD法和磁控濺射(magnetron sputtering deposition, MSD)法制備了錫誘導(dǎo)硅納米線(Sn-SiNWs).通過(guò)掃描電鏡拍攝的圖片(SEM圖)可以看出,PECVD法所制備的Sn-SiNWs的密度、均勻性都要遠(yuǎn)遠(yuǎn)高于MSD所制備的。最后,結(jié)合實(shí)驗(yàn)數(shù)據(jù)討論了SiNWs的生長(zhǎng)機(jī)制。需要指出的是這是首次利用MSD制備出Sn-SiNWs,這在納米級(jí)傳感器、存儲(chǔ)器等微電子器件中有潛在的應(yīng)用前景。另外,如何有效地控制生長(zhǎng)取向一致的SiNWs還有待于進(jìn)一步的研究。
[Abstract]:Hydrogenated nanocrystalline silicon (hydrogenated nanocrystalline silicon, nc-Si:H) thin films are silicon nanocrystals embedded in the hydrogenated amorphous silicon (hydrogenated amorphous silicon, a-Si:H) networks. It has high conductivity, wide band gap, high absorption coefficient, photoluminescence and other photoelectric properties, which have already caused the academic circle. On the one hand, nc-Si:H film materials have quantum confinement effect. Therefore, the band gap can be adjusted by controlling the size of the grain in the thin film, so as to apply to the absorption of light in different bands. On the other hand, the nc-Si:H thin film material has good illumination stability and no obvious photoinduced decay effect. It is used in the industrial production of thin film solar cells. However, the structure and electrical properties of nc-Si:H thin film materials strongly depend on the process parameters prepared. Therefore, the process parameters (RF power, hydrogen) are systematically studied by plasma enhanced chemical vapor deposition (plasma-enhanced chemical vapor deposition, PECVD). The effect of dilution ratio, deposition temperature, phosphorus or boron doping ratio on the crystallization properties, electrical conductivity and growth rate of doped nc-Si:H films. The results show that: (1) in a certain range, with the increase of radio frequency power, the crystallization rate, grain size, deposition rate and electrical conductivity of the intrinsic and doped nc-Si:H films are increasing, but too high. Radio frequency power can make the surface of the film bombarded by a large number of atoms and decrease the conductivity. (2) increasing the ratio of hydrogen dilution is the most effective method to prepare the nc-Si:H thin film. With the increase of the hydrogen dilution ratio, the film gradually transforms from amorphous to nanocrystalline, and the greater the ratio of hydrogen dilution and the higher the degree of crystallization, the deposition rate of the film will be significantly reduced; (3) In a certain range, increasing the deposition temperature can improve the crystallization degree and conductivity of the N and the intrinsic nc-Si:H films, but the P type nc-Si:H thin film is the opposite, mainly because the nc-Si:H film doped with boron is more likely to dehydrogenate at high temperature. (4) the crystallization degree of the thin film is reduced with the increase of the doping ratio of phosphorus or boron, and the deposition rate is at the rate of deposition. In a certain range, the higher the phosphorus doping ratio, the better the conductivity of the film, the higher the boron doping ratio, the worse the conductivity of the thin film, and more than 0.5% of the boron doping ratio will lead to the amorphous film. Finally, the optimum process parameters are selected, and the application of the nc-Si:H film on the p-i-n thin film battery is preliminarily explored, and the highest photoelectric conversion efficiency obtained. 4.97%. metal induced crystallization (metal induced crystallization, AIC) is also one of the common methods to prepare nanocrystalline silicon or silicon nanowires (SiNWs). In this paper, the tin induced silicon nanowires (Sn-SiNWs) are prepared by PECVD method and magnetron sputtering (magnetron sputtering deposition, MSD). It is shown that the density and uniformity of Sn-SiNWs prepared by PECVD method is much higher than that of MSD. Finally, the growth mechanism of SiNWs is discussed with the experimental data. It is necessary to point out that this is the first time to make use of MSD to prepare Sn-SiNWs, which has potential application prospects in nanoscale sensors, memory and other micro devices. SiNWs, which controls the growth orientation uniformly, needs further study.
【學(xué)位授予單位】：浙江師范大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TB383.2

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相關(guān)期刊論文 前1條

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本文編號(hào)：1984306