硼掺杂金刚石薄膜电极电化学特性的研究

本文用未经任何表面处理的硼掺杂金刚石薄膜为电极材料，采用循环伏安法和计时电流法检测含Ｋ３Ｆｅ（ＣＮ）６的ＫＣｌ和ＨＣｌ－ＫＣｌ溶液的响应电流，对电极的基本特性，如响应时间，稳定性等进行了研究；同坟也对溶液ｐＨ值变化与因而造成的响应电流变化进行了研究。从与玻碳电极比较的角度出发，分别在含汞的酸性ＫＣｌ－ＨＮＯ３和中性ＫＣｌ体系中，在一定电位下预富集铅，而后用阳极扫描法检测Ｐｂ－Ｈｇ的溶出峰电流，对金     

Ti/BDD电极和Ti/IrO_2-RuO_2电极降解苯酚的对比研究

研究了两种以Ti为基体,气相法沉积硼掺杂金刚石薄膜(BDD)电极和热分解方法着附IrO2-RuO2涂层电极对工业难降解污染物——苯酚的降解能力。采用循环伏安法,探讨了两种电极的电化学性能。结果表明,以亚甲基蓝作为氧化物的捕获剂,在相同的实验条件下,DSA电极产生氧化物(ClO-)的速度大于BDD电极产生等量氧化物(·OH)的速度。用两种Ti基电极分别降解苯酚溶液48h,BDD电极对苯酚的降解率几乎达到100%,而IrO2-RuO2涂层电极仅为35.6%。苯酚溶液的COD去除率在IrO2-RuO2涂层电极下仅为27.8%,在BDD电极下达到95.3%,且反应产物不易积累。因此,Ti基BDD电极在含芳香类化合物的污水处理方面有较高的应用价值和广阔的推广前景。     

金刚石薄膜连续制备的热丝化学气相沉积设备研制

根据目前热丝化学气相沉积(Hot Filament Chemical Vapour Deposition, HFCVD)金刚石薄膜制备设备现状:存在热丝多为水平放置碳化变脆后易发生断裂、不能实现CVD金刚石薄膜的连续制备、生产成本高及制备效率低等缺点,依据热丝化学气相沉积法制备金刚石薄膜的原理,应用Solidework三维设计软件进行三维建模,结合机械设计软件制图,研制出了该型金刚石薄膜连续制备HFCVD设备,并给出了连续镀膜的工艺流程,采用该设备成功批量生长出质量良好的金刚石薄膜。     

金刚石膜电极的电化学研究

概述了电化学水处理方法、高硼掺杂金刚石膜电极的电化学研究.介绍了高硼掺杂金刚石膜电极的制备、金刚石膜电极在无机和有机废水处理方面的应用.实验表明金刚石膜电极对有代表性的污水具有明显的降解作用,可与其它处理方式结合.     

Ta/BDD薄膜材料电极在检测苯胺中的应用

制作钽衬底掺硼金刚石薄膜材料电极(Ta/BDD),并利用此薄膜材料电极为工作电极通过阴极溶出伏安法检测水中的苯胺.用热丝化学气相沉积(HFCVD)方法沉积Ta/BDD薄膜电极,扫描电镜和拉曼光谱表明电极具有良好的物理性质,循环扫描测试表明电极具有宽的电势窗口4.1V(-1.8～+2.3V vs SCE)和低背景电流,此特性对于电化学检测有着明显的优势.发现苯胺在氧化处理的Ta/BDD电极上有可逆的氧化还原峰,检测过程中未发生电极钝化现象.Ta/BDD电极在酸性介质中苯胺检测效果较明显,苯胺在1～40靘ol/L范围内浓度与溶出峰电流值有较好的线性关系.     

化学气相沉积金刚石薄膜

概述了金刚石膜的发展过程及近年来的发展趋势.阐述了有关的生长机制.对生长金刚石膜非常重要的几个问题有,提高金刚石成份的生长率;稳定金刚石结构,并清洗掉不需要的石墨,引入氢,控制其浓度;或以某种形式赋予石墨以一定能量,使其转变为金刚石.简单的介绍了化学输运过程方法和等离子体动力学方法,总结了研究中已经解决的问题和尚不清楚的问题.收集和整理了金刚石,金刚石膜和类金刚石的性能,进行了对比,并将金刚石膜与一些电子材料进行了比较,最后简述了可能的应用.人造金刚石膜具有优越的性能,这是任何其它材料无法与之比拟的,同时它的造价低廉,因此美国纽约时报惊呼,人造金刚石膜已为电子学、光学、机械加工、化学工业和军事科学开辟了一个新纪元.目前金刚石膜的研制使得东西方的科学家极为振奋,在日本、美国和苏联正在兴起“金刚石热”.     

热丝法化学气相沉积金刚石系统温度分布与薄膜生长关系研究

对热丝化学气相沉积金刚石薄膜系统内的三种传热方式（传导、对流和辐射）进行了比较分析,数值计算了气相空间温度分布和衬底表面二维温度分布。采用热丝化学气相沉积工艺制备了金刚石薄膜,扫描电镜结果显示金刚石薄膜在不同生长区域呈现出与温度分布相关的微观结构与形貌。     

高掺杂Si/BDD薄膜电极的制备及电化学性能

近年来,掺硼金刚石(BDD)膜因具备独特的优异性能而作为电极材料已经受到很大的关注.本文通过MPCVD法在高掺杂硅衬底上生长掺硼金刚石膜,并用四探针、扫描电镜、激光拉曼和电化学工作站对其进行了检测,发现所制备的掺硼金刚石膜电导率达10-2Ω·cm,同时发现金刚石膜质量因硼原子的掺入而有所下降,采用循环伏安法研究其电化学...     

化学气相沉积法制备金刚石薄膜的工业应用

评述了金刚石薄膜的化学气相沉积方法,介绍了金刚石薄膜在工业中的应用前景,并分析了大规模应用所面临的技术困难。     

掺硼金刚石膜的制备及其应用

金刚石虽然具有极为优异的性能,如具有很大的能隙,高的电子迁移率、空穴迁移率和高热导率,以及负的电子亲和势,但要将它用于半导体材料时还不能直接使用,必须要先进行金刚石的P型和n型掺杂。因此,研究金刚石的P型和n型掺杂具有很重要的现实意义。在金刚石薄膜中掺杂时,一般是掺入硼原子以实现P型掺杂,掺入氮原子或磷原子以实现n型掺杂。然而,由于N和P在金刚石中的施主能级太深,现在n型掺杂金刚石薄膜制备尚不成功,这是金刚石实用化的障碍。本文介绍了金刚石膜掺硼目的、方法和制备,总结了掺硼金刚石膜在微电子、电化学、光电子、工具等领域应用状况以及存在问题。     

掺硼金刚石薄膜的电化学性能

利用循环伏安法,通过对比掺硼金刚石薄膜电极和铂／金刚石电极分别作为工作电极时的循环伏安曲线,分析了两种电极表现出的电化学性能差别,并利用能级理论进行了机理探讨。结果表明掺硼金刚石薄膜电极具有宽的电化学窗口（宽度约为3V）、良好的化学稳定性和极低的背景电流（接近0）,是一种较有潜力的电化学电极材料。     

直流热阴极CVD金刚石薄膜生长特性研究

为了获得高质量的金刚石薄膜,采用直流热阴极化学气相沉积系统分别在不同基片温度和不同碳源气体含量条件下生长金刚石薄膜,利用Raman光谱、SEM和XRD检测方法研究了基片温度和碳源气体含量对金刚石薄膜生长特性的影响.结果表明,金刚石薄膜与基片Mo之间有Mo2C的过渡层存在;1000℃的温度能够促进金刚石晶体的生长,抑制其他碳杂质的形成,CH4体积分数为2%适于快速生长高纯度的金刚石薄膜.     

热灯丝CVD金刚石膜的微结构和形貌对其电子性质的影响

利用热灯丝CVD法在硅衬底上合成出了金刚石膜。金刚石膜的质量和电子性质由扫描电子显微镜、拉曼谱、阴极发光及霍尔系数测量来表征。实验结果表明,沉积条件对金刚石膜电子性质和质量有重要影响。载流子迁移率随甲烷浓度增加而减少,但场发射随其增加而增强。压阻效应随微缺陷增多而降低。异质外延金刚石膜压阻因子在室温下100微形变时为1200,但含有大量缺陷的多晶金刚石膜压阻因子低于200,这是由于薄膜中缺陷态密度增加,并依赖于膜结构的变化。     

等离子热丝化学气相沉积金刚石膜工艺参数研究

采用等离子热丝化学气相沉积(PHFCVD)装置进行了金刚石薄膜的制备实验。实验条件为：氢气流量为200sccm,甲烷流量为2～12sccm,基体温度为700～900℃,偏压为0～400V,真空室压力为4kPa。通过实验得出了甲烷含量、基体温度和偏压对沉积金刚石膜的影响,并运用扫描电子显微镜(SEM)、原子力显微镜(AFM)和X射线衍射(XRD)等测试方法对金刚石薄膜进行了观察分析。     

不同氩气与氢气流量比对硼掺杂纳米金刚石膜的影响

采用直流热阴极PCVD方法,以B(OCH3)3作为硼源,通过改变氩气与氢气流量比,在p型Si衬底上沉积了硼掺杂纳米金刚石膜.研究了不同氩气与氢气流最比对掺硼金刚石膜生长的影响.采用扫描电子显微镜、拉曼光谱仪、X射线衍射仪、霍尔系统等对样品的形貌、结构和导电性能进行了表征.结果表明,随着氩气与氢气流量比的增加,膜的晶粒尺寸由微米级向纳米级转变,并且膜中非晶碳成分增多,膜的导电性能变好.     

Poly-crystalline silicon thin films prepared by plasma-assisted hot-wire chemical vapor deposition

A combination of hot-wire chemical vapor deposition (HWCVD) and RF plasma, referred to as plasma-assisted HWCVD (P-HWCVD) was used to prepare poly-crystalline silicon (poly-Si) thin films. The effects of the plasma on the film properties were studied by varying the RF power (P_w) from 0 to 40 W. The results indicate that, compared with that of HWCVD samples, the film crystalline fraction (X_c) is enhanced at low P_w assistance, whereas it decreases at higher P_w. The uniformity of the film thickness is considerably improved by introducing plasma. It is also found that the porosity of the film, indirectly detected from infrared spectra, is much reduced. Auger analysis of the tantalum filament used in the P-HWCVD process shows much lower silicon contamination than that in HWCVD.     

Transverse bias-enhanced nucleation of diamond in hot filament chemical vapor deposition

 The nucleation density of diamond films was greatly enhanced by inserting a transverse bias into hot filament vapor deposition chamber, which differs from the conventional used longitudinal bias method. In-situ Optical Emission Spectroscopy (OES) technique was used to investigate the diamond deposition process. The relative optical emission intensities of the atomic hydrogen and CH radical to argon near the substrate were calculated. The results show that the improvement of the nucleation density is due to the product of much more atomic hydrogen and CH radicals. Received: 18 March 1998 / Accepted: 22 May 1998     

Applicability of boron-doped diamond electrode to the degradation of chloride-mediated and chloride-free wastewaters

The electrochemical degradation of chloride-mediated and chloride-free dye wastewaters was investigated on a boron-doped diamond (BDD) electrode in comparison with that on a dimensionally stable anode (DSA), and the applicability of BDD electrode to the degradation of these two kinds of wastewaters was explored. In chloride-free wastewater, the electrochemical degradation efficiency of dye on BDD electrode was much higher than that on DSA, with a chemical oxygen demand (COD) removal of 100% and 26% for BDD and DSA, respectively. In chloride-mediated dye wastewater, COD removal was faster than that in chloride-free wastewater on both BDD and DSA electrodes with COD removal efficiencies higher than 95%, whereas the rate of COD removal on DSA was faster than that on BDD electrode. The investigation indicates that DSA is more suitable than BDD electrode in degradation of originally chloride contained dye wastewaters for the sake of energy and time saving. However, for chloride-free dye wastewaters, with the aim of environmental protection, BDD electrode is more appropriate to realize complete mineralization. At the same time, the secondary pollution can be avoided.     

XPS study of carbon nitride films deposited by hot filament chemical vapor deposition using carbon filament

Amorphous carbon nitride, a-CN_x, thin films were deposited by hot filament CVD using a carbon filament with dc negative bias voltage on the substrate. The effects of the negative bias and the filament components on the binding structure of the films are investigated by XPS. The composition ratio of graphite to amorphous carbon in the filaments affects the bonding structure of carbon and nitrogen in the films, although the nitrogen content in the films is almost same as 0.1. The nitrogen content in the films changes from 0.1 to 0.3 as the negative bias changes from 0 to − 300 V.