本文選題：ZnS薄膜 + 化學水浴法��； 參考：《鄭州大學》2015年碩士論文

【摘要】：在諸多半導體材料中,Zn S是一種重要的禁帶寬度為3.7 e V半導體材料,在光電等方面有廣泛的應用。對Zn S薄膜進行摻雜和熱退火處理可以明顯的改善Zn S薄膜的物理、化學等性能,在摻雜方面Zn S薄膜的n型摻雜尤為重要,為以后的p-n結的制備打下基礎。本文利用化學水浴法合成了多晶的Zn S薄膜和Zn S:Al3+薄膜,深入研究了樣品的微結構和光學性質。主要的研究結果有:(1)當氨水作為絡合劑和p H值調節(jié)劑時,光快速熱處理并沒有導致非晶態(tài)的Zn S薄膜的結晶,這顯示硅襯底上水浴制備結晶的Zn S薄膜單采用氨水作為絡合劑是不行的;隨著Thermal Treatment Temperature(Trtt)的升高,Zn S薄膜顆粒有比較明顯的細化趨勢,顆粒尺寸分布趨于均勻,表面粗糙度趨于減小,這可能是歸結于光快速熱處理過程中顆粒的重新排列和生長;薄膜的吸收邊隨Trtt總體趨于紅移,該紅移可歸結于薄膜的應力的變化;Trtt的升高起初增大了薄膜中的點缺陷,隨后由于薄膜內部的原子重新排列,點缺陷減少。值得注意是當Trtt300℃時,與點缺陷相關的發(fā)光峰幾乎消失。(2)采用三乙醇胺作為絡合劑,氨水作為p H值調節(jié)劑,在重摻雜的p型Si(100)襯底上合成了Zn O薄膜而不是Zn S薄膜,這可能歸咎于Zn S的水解;選用乙二胺作為絡合劑,當p H值為4時,制備出了結晶質量較好的Zn S薄膜。(3)選用乙二胺作為絡合劑,研究了乙二胺濃度對Zn S性質的影響。所制備的Zn S由立方相和少量的六方相組成。未加入乙二胺時,薄膜表面粗糙,出現(xiàn)了明顯的顆粒團聚現(xiàn)象。隨著乙二胺濃度的增加,薄膜表面趨于光滑和致密,可以看出絡合劑在改善薄膜表面方面扮演著重要的角色。光學吸收邊隨乙二胺濃度的增加會藍移,這歸結于薄膜中應力的影響。所有樣品的發(fā)射光譜均在可見光區(qū)呈現(xiàn)了寬的發(fā)射帶,這與薄膜中的點缺陷(鋅空位和硫空位)有關。(4)前驅物鋅離子濃度(CZn)對Zn S薄膜性能的影響很明顯。當CZn為0.25 M時,XRD譜中觀測不到明顯的Zn S特征衍射峰,這表明在這種濃度下很難生成Zn S薄膜,或生成的薄膜結晶性不好,呈現(xiàn)非晶態(tài)。隨著CZn的增加,薄膜的結晶性得到明顯改善。(5)本征的Zn S薄膜的電阻率為1.5×107Ωcm,當Al Cl3為1.0 mmol時,電阻率降至4.2×102Ωcm,然后又隨著Al Cl3的增加而有所增大。薄膜電阻率起初的降低歸結于部分Al3+對Zn2+的替代和薄膜結晶性的改善,前者會引起薄膜中自由載流子濃度的增加,而后者會提高自由載流子的遷移率。而后電阻率的增加可歸咎于晶界散射的增強。
[Abstract]:ZNS is a kind of important semiconductor material with a band gap of 3.7 EV, which has been widely used in the field of photoelectricity and so on. Doping and thermal annealing of ZnS thin films can obviously improve the physical and chemical properties of ZnS films. The n-type doping of ZnS films is particularly important in doping aspect, which lays the foundation for the preparation of p-n junctions in the future. Polycrystalline ZnS and Zn S:Al3 thin films were synthesized by chemical bath method. The microstructure and optical properties of the samples were studied. The main results are as follows: (1) when ammonia is used as a complexing agent and pH value regulator, rapid photothermal treatment does not result in the crystallization of amorphous ZnS films. The results show that it is not possible to use ammonia water as complexing agent to prepare crystalline ZnS thin films on Si substrates in water bath, and the grain size distribution tends to be uniform with the increase of Thermal Treatment temperature trtt. The surface roughness tends to decrease, which may be attributed to the rearrangement and growth of the particles during the photorapid heat treatment, and the absorption edge of the film tends to redshift with the Trtt as a whole. The redshift can be attributed to the change of stress in the film. The increase of Trtt initially increases the point defect in the film, then decreases the point defect due to the rearrangement of atoms in the film. It is worth noting that, at Trtt300 鈩，

本文編號：1940769