本文選題：GaAs納米線 + 表面鈍化　； 參考：《物理學(xué)報(bào)》2017年19期

【摘要】：納米線表面存在大量的表面態(tài),它們能夠引起電子分布在納米線表面,使得納米線的電學(xué)性質(zhì)對(duì)表面條件變得更加敏感,嚴(yán)重地制約器件的性能.表面鈍化能夠有效地移除納米線的表面態(tài),進(jìn)而能夠有效地優(yōu)化器件的性能.采用基于密度泛函理論的第一性原理計(jì)算方法研究了表面鈍化效應(yīng)對(duì)GaAs納米線電子結(jié)構(gòu)性質(zhì)的影響.考慮了不同的鈍化材料,包括氫元素、氟元素、氯元素和溴元素.研究結(jié)果表明:具有小尺寸的GaAs裸納米線的能帶結(jié)構(gòu)呈間接帶隙特征,表面經(jīng)過完全鈍化后,轉(zhuǎn)變?yōu)橹苯訋短卣?GaAs納米線表面經(jīng)過氫元素不同位置和不同比例鈍化后,展示出不同的電學(xué)性質(zhì);表面鈍化的物理機(jī)理是鈍化原子與納米線表面原子通過電荷補(bǔ)償移除納米線表面的電子態(tài);與氫元素鈍化相比,GaAs納米線表面經(jīng)過氟元素、氯元素和溴元素鈍化后,帶隙寬度較小,原因是氟元素、氯元素和溴元素在鈍化過程中具有較小的電荷補(bǔ)償能力,不能完全移除表面態(tài).
[Abstract]:There are a large number of surface states on the surface of nanowires, which can cause electrons to distribute on the surface of nanowires, which makes the electrical properties of nanowires more sensitive to surface conditions and severely restricts the performance of devices. Surface passivation can effectively remove the surface state of nanowires and then optimize the device performance. The effect of surface passivation on the electronic structure of GaAs nanowires was studied by using the first principle method based on density functional theory. Different passivation materials were considered, including hydrogen, fluorine, chlorine and bromine. The results show that the energy band structure of the bare GaAs nanowires with small size exhibits indirect band gap characteristics. After the surface is completely passivated, the GaAs nanowire surface is transformed into a direct band gap feature. The surface of the GaAs nanowires is passivated by hydrogen elements at different positions and in different proportions. The physical mechanism of surface passivation is that the passive atoms and the surface atoms of nanowires remove the electronic states of the nanowires by charge compensation, and the surface of GaAs nanowires undergo fluorine in comparison with hydrogen passivation. After the passivation of chlorine and bromine, the band gap width is smaller, because fluorine element, chlorine element and bromine element have smaller charge compensation ability in the passivation process, and the surface state can not be completely removed.
【作者單位】： 湖南工學(xué)院數(shù)理科學(xué)與能源工程學(xué)院;廣西師范學(xué)院物理與電子工程學(xué)院;
【基金】：國(guó)家自然科學(xué)基金(批準(zhǔn)號(hào):11704112,11547197,61640405,61704036) 湖南省自然科學(xué)基金(批準(zhǔn)號(hào):2017JJ3051,2017JJ2062) 湖南省教育廳科研項(xiàng)目(批準(zhǔn)號(hào):17B066,17B065,16A052) 衡陽市科技計(jì)劃項(xiàng)目(批準(zhǔn)號(hào):2016KJ14) 湖南工學(xué)院大學(xué)生創(chuàng)新訓(xùn)練計(jì)劃項(xiàng)目(批準(zhǔn)號(hào):HX1608) 湖南省大學(xué)生研究性學(xué)習(xí)和創(chuàng)新性實(shí)驗(yàn)計(jì)劃項(xiàng)目資助的課題~~
【分類號(hào)】：TB383.1
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本文編號(hào)：1800431