【摘要】：半導(dǎo)體納米材料由于其特有的光電性能,且在未來(lái)器件小型化發(fā)展趨勢(shì)方面具有潛在的應(yīng)用價(jià)值,因而一直是納米材料科學(xué)中的研究熱點(diǎn)。作為一種重要的寬禁帶半導(dǎo)體材料,Ga N納米材料的可控制備、發(fā)光性能以及能帶結(jié)構(gòu)中深能級(jí)行為一直是研究的熱點(diǎn)問題。同時(shí),最近的研究發(fā)現(xiàn),Ga N基納米材料具有吸收可見光使水解離產(chǎn)生氫的性能,這使得不同形貌Ga N納米材料的制備和發(fā)光性能的研究再次獲得廣泛關(guān)注。本文采用固相源化學(xué)氣相傳輸法,通過金屬Ga和氨氣直接反應(yīng),無(wú)催化劑輔助的條件下,在石英襯底上制備出了多種形貌的Ga N納米結(jié)構(gòu),利用X射線衍射儀(XRD)、掃描電子顯微鏡(SEM)、拉曼(Raman)光譜儀以及光致發(fā)光(PL)譜對(duì)所制備的Ga N納米結(jié)構(gòu)進(jìn)行了表征和發(fā)光性能的研究。研究結(jié)果如下:1、在0.1個(gè)大氣壓范圍內(nèi),無(wú)催化劑輔助的石英襯底上能夠制得Ga N納米結(jié)構(gòu)。納米結(jié)構(gòu)是由納米晶沿著其適宜的生長(zhǎng)方向堆疊而成,由于不同生長(zhǎng)溫度導(dǎo)致金屬Ga蒸汽壓濃度不同,因而合成的納米結(jié)構(gòu)具有形貌多樣性。Ga N納米結(jié)構(gòu)的Raman光譜中,A1(LO)模式相對(duì)于體相產(chǎn)生了紅移,可歸因于聲子限域效應(yīng)。Ga N納米結(jié)構(gòu)的光致發(fā)光包括本征發(fā)光和缺陷發(fā)光,其缺陷發(fā)光機(jī)制為淺施主能級(jí)到價(jià)帶或淺施主能級(jí)到深受主能級(jí)間的輻射發(fā)光。2、常壓時(shí),無(wú)催化劑輔助條件下,在鎵源附近和石英襯底上均制得Ga N納米結(jié)構(gòu)。通過改變升溫方式、溫度、氨氣流量以及反應(yīng)時(shí)間等手段能夠控制纖鋅礦Ga N納米結(jié)構(gòu)的形貌。隨著反應(yīng)溫度的升高,晶粒尺寸變大。當(dāng)合成溫度達(dá)到900℃時(shí),晶體的結(jié)晶質(zhì)量變好。當(dāng)反應(yīng)時(shí)間變長(zhǎng)時(shí),晶體的結(jié)晶質(zhì)量變好。與負(fù)壓下合成的Ga N納米結(jié)構(gòu)相比,常壓下合成的納米結(jié)構(gòu)的結(jié)晶質(zhì)量更好。光致發(fā)光中缺陷發(fā)光隨著粒徑的減小會(huì)產(chǎn)生紅移,可歸因于深受主能級(jí)存在一定的波動(dòng)范圍。3、Ga N納米結(jié)構(gòu)摻Zn后會(huì)形成包覆結(jié)構(gòu),尺寸增加,樣品變厚,說(shuō)明Zn摻雜能提高Ga的蒸氣壓濃度。同時(shí)XRD圖譜的峰位產(chǎn)生微小左移,晶格常數(shù)略微增大,衍射峰的峰形更加明顯,說(shuō)明Zn摻雜能夠改善Ga N納米結(jié)構(gòu)的結(jié)晶度。
[Abstract]:Semiconductor nanomaterials, due to their unique optoelectronic properties and potential applications in miniaturization of devices in the future, have been the focus of research in nanomaterial science. As an important wide band gap semiconductor material, Ga N nanomaterials controlled preparation luminescent properties and deep level behavior in the energy band structure has been a hot topic. At the same time, recent studies have found that, Ga N based nanomaterials have the ability of absorbing visible light to dissociate water to produce hydrogen, which makes the preparation and luminescence properties of different morphologies of Ga N nanomaterials receive more and more attention. In this paper, various morphologies of Ga N nanostructures were prepared on quartz substrates by solid source chemical vapor transport method by direct reaction of metal Ga with ammonia gas and without catalyst. (XRD), was used by X-ray diffractometer. Scanning electron microscopy (SEM) (SEM), Raman (Raman) spectrometer and photoluminescence (PL) spectroscopy were used to characterize and characterize the Ga N nanostructures. The results are as follows: 1. In the range of 0.1 atmospheres, Ga N nanostructures can be prepared on quartz substrates without catalyst. The nanostructures are stacked by nanocrystalline along its proper growth direction. Due to the different growth temperature, the Ga vapor pressure concentration is different, so the synthesized nanostructures have a variety of. Ga N nanostructures in the Raman spectra. The A1 (LO) mode has a red shift relative to the bulk phase, which can be attributed to the phonon limiting effect. The photoluminescence of. Ga N nanostructures includes intrinsic luminescence and defect luminescence. The mechanism of defect luminescence is luminescence from shallow donor energy level to valence band or from shallow donor energy level to deep principal energy level. 2. At atmospheric pressure, Ga N nanostructures are prepared near gallium source and on quartz substrate under the condition of no catalyst. The morphology of wurtzite Ga N nanostructures can be controlled by changing the temperature, ammonia flow rate and reaction time. The grain size increases with the increase of reaction temperature. When the synthesis temperature reaches 900 鈩，

本文編號(hào)：2317900