發(fā)布時間：2018-05-18 20:31

  本文選題：水熱法 + 黃鐵礦��； 參考：《電子科技大學(xué)》2015年碩士論文

【摘要】：黃鐵礦FeS2作為一種儲量豐富、無毒的化合物半導(dǎo)材料,具備理想的禁帶寬度(0.95 eV),高光吸收系數(shù)(~105 cm-1,hν1.3 eV)和遷移率(~360 cm2V-1s-1)等優(yōu)異光電性能,因而在太陽能電池與光電探測領(lǐng)域備受關(guān)注。本文采用了低成本、綠色環(huán)保和簡單可控的水熱法,以FeCl2·4H2O與S粉為主要原料,明膠為表面活性劑實現(xiàn)了純相黃鐵礦納米單晶的快速合成,并利用XRD、SEM、HRTEM、EDS、UV-vis等方法對黃鐵礦進行了性能表征。然后,進一步研究了不同反應(yīng)時間和S/Fe摩爾比對納米單晶的成分、結(jié)構(gòu)、形貌及缺陷的影響。最后,通過制備簡易的光電探測器對其光電性能進行了分析。本文主要得到以下主要研究成果:1)水熱法制備黃鐵礦納米單晶實驗在S/Fe=3.75/1,t=48 h,pH=12.3,T=200℃的條件下得到黃鐵礦納米單晶,無白鐵礦、FexO1-x等雜質(zhì);晶格常數(shù)a=0.5417 nm,尺寸分布在20~40 nm;主要呈球狀、立方狀和多面體,活性劑的分解導(dǎo)致晶粒間團聚比較嚴(yán)重。2)黃鐵礦納米單晶合成工藝的優(yōu)化在S/Fe=2.5/1不同反應(yīng)時間(12、24、48 h)條件下,時間越短,FexO1-x越多,形貌多呈球狀,尺寸較小且分布均勻,無團聚現(xiàn)象;時間越長,黃鐵礦增加,形貌呈球狀、立方體等,尺寸變大,分布范圍更大,出現(xiàn)團聚現(xiàn)象。在反應(yīng)時間為24 h、不同S/Fe摩爾比(1/1.5、1/0.75、2.5/1)的條件下,摩爾比越小,反而越有利于黃鐵礦的生長,形貌多為球狀,尺寸較小且分布均勻,無團聚現(xiàn)象;摩爾比增加,黃礦鐵先減弱后增強,結(jié)晶程度先降低后上升,晶粒平均尺寸變大,分布范圍變大,有較輕團聚現(xiàn)象。在反應(yīng)時間為48 h、不同S/Fe摩爾比(2.5/1、3/1、3.75/1)的條件下,S/Fe摩爾比越高,黃鐵礦越純,并在S/Fe=3.75/1條件下獲得純相黃鐵礦納米單晶,形貌從球狀向立方體與不規(guī)則的多面體過渡,晶粒的團聚現(xiàn)象減弱,但尺寸明顯變大,分布區(qū)間也較大。3)黃鐵礦納米單晶的光電性能通過光刻工藝、電子束蒸發(fā)與聚焦離子束刻蝕等技術(shù)制備簡易的光電探測原型器件,隨后在器件上利用滴涂技術(shù)與高溫退火制備致密且厚度均勻的薄膜,在光照條件下測得電流密度為1~102 mA●cm-2;由于量子尺寸效應(yīng)等因素造成光吸收藍移,通過UV-vis光吸收譜計算出禁帶寬度Eg=1.53 eV,高于理論值。
[Abstract]:As a kind of abundant and nontoxic compound semiconductors, pyrite FeS2 has excellent optoelectronic properties, such as ideal bandgap 0.95 EV, high light absorption coefficient 105cm-1h v 1.3 EV) and mobility of 360cm2V-1s-1). As a result, solar cells and photoelectric detection have attracted much attention. In this paper, the rapid synthesis of pure pyrite nanocrystalline was realized by using FeCl2 4H2O and S powder as main raw materials and gelatin as surfactant by using low cost, green environmental protection and simple and controllable hydrothermal method. The properties of pyrite were characterized by the methods of XRDX SEMU HRTEMU EDS- UV-vis and so on. Then, the effects of different reaction time and molar ratio of S/Fe on the composition, structure, morphology and defects of nanocrystalline were studied. Finally, the photoelectric properties of the photodetectors are analyzed by the preparation of simple photodetectors. In this paper, the following main research achievements have been obtained: the hydrothermal method of preparing pyrite nanocrystalline has been studied. At the condition of S / FeN 3.75 / 1 ~ (-1) h ~ (-1) ~ (-1) h ~ (-1) pH ~ (12. 3) T ~ (-1) T ~ (2 +) ~ (200 鈩，

本文編號：1907100