本文關(guān)鍵詞：白光LED用鈦酸鹽紅色熒光粉的制備與性能研究　出處：《安徽理工大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 稀土摻雜 溶膠-凝膠法 鈦酸鋅 鈦酸鍶 發(fā)光性能 紅色熒光粉

【摘要】：白光LED由于具有能耗低綠色環(huán)保等優(yōu)勢被稱為第四代光源,其在照明領(lǐng)域的持續(xù)發(fā)展吸引了廣大科研工作者,并且在市場上的潛力不斷擴(kuò)大。在LED用三基色熒光粉中,紅色熒光粉用量最多,但是紅色熒光粉的穩(wěn)定性以及效率等方面亟需改善,所以,研究高性能紅色熒光粉,是目前白光LED熒光粉研究中的重點(diǎn)。在本文中,我們采用溶膠-凝膠法首先制備了 ZnTi03基質(zhì)和Zn1-xTi03:xEu3+熒光粉,通過X射線衍射、掃描電鏡和透射電鏡等分析研究了樣品的物相結(jié)構(gòu)和微觀形貌。結(jié)果表明,ZnTiO3基質(zhì)和Zn1-xTi03:xEu3+樣品都是偏六方相結(jié)構(gòu)。熒光光譜表明Zn1-xTiO3:xEu3+熒光粉的激發(fā)峰峰位分別在393nm和464nm處,發(fā)射峰在615nm處。研究表明,當(dāng)Eu3+摻雜濃度為2mol%,鍛燒溫度為700℃,保溫時(shí)間為4h時(shí),樣品的發(fā)光強(qiáng)度最大。樣品Zn0.98Ti03:0.02Eu3+的色坐標(biāo)為(x=0.673,y=0.327),十分接近于國際照明協(xié)會(huì)NTSC規(guī)定的純紅色坐標(biāo)(x=0.670,y=0.330),具有較高的色純度。通過在Zn0.98TiO3:0.02Eu3+熒光粉中添加不同濃度的堿金屬離子A+(A=Li、Na、K),研究其熒光增強(qiáng)效應(yīng)。熒光光譜表明添加堿金屬離子Li+、Na+、K+的摻雜對(duì)ZnTi03:Eu3+熒光粉的發(fā)光強(qiáng)度均有不同程度的提高,其中添加Li+對(duì)Zn0.98TiO3:0.02Eu3+熒光粉的發(fā)光強(qiáng)度提高最為明顯,約是沒摻雜堿金屬離子樣品發(fā)光強(qiáng)度的2.14倍。Na+和K+的摻雜分別提高了 1.55倍和1.45倍。采用溶膠-凝膠法制備了 Sr1-xTiO3:xEu3+以及Sri-xTiO3:xEu3+,yA+熒光粉。XRD和TEM圖表明樣品SrTi03基質(zhì)和Sri-xTi03:xEu3+都呈現(xiàn)立方相結(jié)構(gòu)。激發(fā)光譜表明Sri-xTiO3:xEu3+熒光粉在465nm波長的光激發(fā)下,可以發(fā)射出峰值在580 nm,591nm和617nm波長的光,在Eu3+和堿金屬離子摻雜濃度為4mol%時(shí),樣品的發(fā)光效果最好。其中K+的引入對(duì)SrTi03:Eu3+樣品發(fā)光性能提高幅度最大。用第一性原理模擬計(jì)算了 Eu3+摻雜、和Eu3+/Li+共摻雜的ZnTiO3和SrTiO3電子結(jié)構(gòu)及光學(xué)性質(zhì).計(jì)算結(jié)果表明:Eu3+摻雜和Eu3+/Li+共摻雜的帶隙有所降低,這大概是因?yàn)橛幸恍〦u4f的雜質(zhì)態(tài)出現(xiàn)在禁帶。Eu3+/Li+共摻雜的協(xié)同效應(yīng)增強(qiáng)了各電子之間的耦合作用,促進(jìn)了體系間能量的傳遞,從而增強(qiáng)發(fā)光強(qiáng)度。另外,光學(xué)吸收譜表明了 Eu3+/Li+共摻雜的ZnTi03和SrTi03出現(xiàn)了明顯的光吸收紅移現(xiàn)象,并在低能區(qū)顯示出更強(qiáng)的光吸收能力,這些結(jié)果均表明Eu3+/Li+共摻雜的協(xié)同效應(yīng)能很好的增強(qiáng)在可見光區(qū)域的發(fā)光強(qiáng)度,與實(shí)驗(yàn)結(jié)果相吻合。
[Abstract]:White LED is called 4th generation light source because of its advantages of low energy consumption and low green environment. Its sustainable development in the field of lighting has attracted many researchers. And the potential in the market continues to expand. In the LED tricolor phosphors, the amount of red phosphors is the most, but the stability and efficiency of red phosphors need to be improved. The research of high performance red phosphors is the focus of white LED phosphors. ZnTi03 and Zn1-xTi03:xEu3 phosphors were prepared by sol-gel method. The phase structure and microstructure of the samples were studied by SEM and TEM. Both ZnTiO3 matrix and Zn1-xTi03:xEu3 have hexagonal phase structure. Fluorescence spectra show that Zn1-xTiO3:xEu3. The excitation peaks of the phosphors are at 393nm and 464nm, respectively. The emission peak is at 615nm. The results show that when the doping concentration of Eu3 is 2 mol / L, the calcination temperature is 700 鈩，

本文編號(hào)：1391146