本文選題：半導(dǎo)體 + 納米晶�。� 參考：《華中農(nóng)業(yè)大學(xué)》2015年碩士論文

【摘要】：半導(dǎo)體納米材料具有許多特殊的光學(xué)、電學(xué)、化學(xué)和磁學(xué)性質(zhì),這些性質(zhì)很大程度上受到材料的形貌和尺寸的影響,因此可控的合成半導(dǎo)體納米材料一直受到廣泛的關(guān)注。碲、硒和碲硒晶半導(dǎo)體材料擁有低的熔點、良好的光導(dǎo)性、熱電性能和氧化還原能力,在合成功能材料和納米級設(shè)備的制備上展現(xiàn)出潛在的應(yīng)用價值。但在目前的研究中碲硒晶納米材料的研究并不多,而且其形貌多樣性和合成方法有很大的改進空間。本論文研究了可控合成不同形貌的均相(homogeneous)三方碲硒納米晶(trigonal Te/Se alloy nanocrystals,t-Te/Se ANCs)。我們采用常溫水相法合成碲硒晶納米材料,合成方法簡單環(huán)保且可以大批量合成。主要研究結(jié)果如下:1.調(diào)控前體Te O2與H2Se O3的比例(x(Te:Se))合成形貌多樣,縱橫比、成分可控的t-Te/Se ANCs。通過調(diào)控x(Te:Se)的值,t-Te/Se ANCs主要會按照兩種方式生長:第一種,當(dāng)x(Te:Se)的值從200:1到100:1或者從2:1到1:1的時候,生長成獨個三方碲硒納米晶(trigonal Te/Se alloy single nanorods,t-Te/Se ASNRs);第二種,當(dāng)x(Te:Se)從30:1到10:1的時候生長成三連體的三方碲硒納米晶(trigonal Te/Se alloy tri-fold nanorods,t-Te/Se ATNRs)。這些納米晶通過自籽結(jié)晶過程形成生長方向沿[001]方向生長的均相單晶。2.表征了t-Te/Se ANCs的紫外可見吸收光譜、晶體結(jié)構(gòu)、組成成分和拉曼光譜。隨著t-Te/Se ANCs長度和x(Te:Se)的變化,t-Te/Se ANCs的紫外、晶體結(jié)構(gòu)、組成成分和拉曼也存在一系列規(guī)律性的變化。當(dāng)t-Te/Se ANCs長度的減小時,t-Te/Se ANCs的紫外峰會發(fā)生紅移。隨x(Te:Se)值的減小,t-Te/Se ANCs的晶體結(jié)構(gòu),組成成分和拉曼光譜與三方硒(trigonal Se,t-Se)趨于相同。3.分析論證了不同形貌t-Te/Se ANCs自籽結(jié)晶過程的機理。從碲硒納米晶不同反應(yīng)階段的透射電鏡圖看出,t-Te/Se ASNRs與t-Te/Se ATNRs的生長是兩個不同的結(jié)晶成核過程。在t-Te/Se ASNRs的形成過程中,只存在一次成核結(jié)晶,t-Te/Se ASNRs由最初的小六棱柱(核子)逐漸結(jié)晶長大;而t-Te/Se ATNRs的形成是存在兩次成核結(jié)晶過程,先結(jié)晶成核為小六棱柱,然后選擇性的自動在小六棱柱的三個面結(jié)晶成核為另外的三個小六棱柱核子,隨著這三個小六棱柱的長大最終形成t-Te/Se ATNRs。這可能是由于Te,Se兩種元素有不同的化學(xué)和晶體學(xué)性質(zhì),因此兩者最終形成的納米棒的形貌會因兩者的比例不同而有所不同。
[Abstract]:Semiconductor nanomaterials have many special optical, electrical, chemical and magnetic properties. These properties are greatly affected by the morphology and size of the materials, so controllable synthetic semiconductor nanomaterials have been widely concerned. Tellurium, selenium and selenium tellurium crystal semiconductor materials have low melting point, good photoconductivity, thermoelectric properties and redox ability, which show potential applications in the preparation of functional materials and nanoscale equipment. However, there is not much research on se Te nanocrystalline materials, and there is much room for improvement in their morphology diversity and synthesis methods. In this paper, trigonal Ter se alloy nanocrystals t-Ter se nanocrystals with different morphologies have been synthesized by controlled synthesis. Se Te nanocrystalline materials were synthesized by water phase method at room temperature. The synthesis method is simple and environmentally friendly and can be synthesized in large quantities. The main results are as follows: 1. The ratio of Te-O _ 2 to H _ 2Se _ 3 (x (: se) was characterized by various morphologies, aspect ratio, and controllable composition of t-Ter se ANCs. By regulating the value of x (team: se), t-Ter / se ANCs grow mainly in two ways: first, when the value of x (team: se) ranges from 200: 1 to 100: 1 or from 2:1 to 1:1, they grow into trigonal Ter. E alloy single nanorodst-TeSe ASNRs. From 30:1 to 10:1, the trigonal Ter. E alloy tri-fold nanorodsm t-Ter se ATNRs were grown from 30:1 to 10:1. These nanocrystals form homogenous crystal. 2. 2 in the direction of growth along [001] direction through the process of self-seed crystallization. The UV-Vis absorption spectra, crystal structure, composition and Raman spectra of t-Ter / se ANCs were characterized. With the variation of t-Ter / se ANCs length and x (team: se), there are a series of regular changes in the UV, crystal structure, composition and Raman of t-Ter / se ANCs. When the length of t-Ter / se ANCs decreases, the UV summit of t-TeP / se ANCs redshifts. With the decrease of the value of x (TeSe), the crystal structure, composition and Raman spectra of t-Te-Se ANCs tend to be the same as that of trigonal Sea-t-Se. The mechanism of self-seed crystallization of t-Ter / se ANCs with different morphologies was analyzed and demonstrated. Transmission electron microscopy (TEM) of selenium tellurium nanocrystals shows that the growth of t-Ter / se ASNRs and t-Ter / se ATNRs are two different nucleation processes. In the formation of t-Ter / se ASNRs, there is only one nucleation and crystallization of t-TeP / se ASNRs, and the formation of t-Ter / se ASNRs gradually grows from the initial small hexagonal prism (nucleon), while the formation of t-Ter / se ATNRs is a process of two nucleation and nucleation, and the first crystallization is a small hexagonal prism. Then the nucleation of the other three small hexagonal prism nucleates automatically on the three sides of the small hexagonal prism, and as these three small hexagonal prisms grow up, the t-Ter / se ATNRss are finally formed. This may be due to the different chemical and crystallographic properties of the two elements, so the morphology of the nanorods formed by the two elements will be different depending on the ratio of the two elements.
【學(xué)位授予單位】：華中農(nóng)業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TB383.1

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