【作者】 薛进奎；

【导师】 王海燕；

【作者基本信息】 郑州大学 ， 凝聚态物理， 2011， 硕士

【摘要】 掺铝氧化锌(AZO)透明导电薄膜由于电阻率低、在可见光区域透射率高且织构后的绒面结构能有效地对入射光起到减反作用,增加光的吸收,提高薄膜太阳电池光电转换效率,所以被广泛应用于薄膜太阳能电池前电极。制备既有优良的光电性能又有比较大的绒度且表面形貌均匀的绒面AZO薄膜对其在薄膜太阳电池中的应用、进一步降低太阳电池生产成本和实现大规模产业化生产极其重要。目前采用磁控溅射技术制备的AZO薄膜经0.5%的稀HCl刻蚀后可以实现优良的表面织构,但要获得大面积均匀且有较高绒度的AZO绒面一般还比较难,所以解决AZO薄膜的表面织构均匀性问题对AZO薄膜的广泛应用有极其重要的意义。本文采用一定配比的稀盐酸与醋酸混合腐蚀溶液对AZO薄膜进行刻蚀,研究制备工艺和腐蚀溶液中醋酸对刻蚀后的薄膜结构、光电性能和表面形貌均匀性的影响,分析其表面反应机理,以期望对AZO薄膜大面积织构均匀性有一定的指导性意义。本文用Al2O3掺杂质量分数2%的Al2O3/ZnO陶瓷靶材,在(O2+Ar)气氛下,采用直流磁控溅射在玻璃衬底上制备AZO薄膜,然后用湿法刻蚀法获得绒面AZO薄膜。利用传统四探针、HMS-3000Hall测试仪、UV-3150型IR-VIS-UV紫外可见光分光光度计、扫描电子显微镜(SEM)分别研究工艺参数和腐蚀溶液对AZO薄膜腐蚀前后的电学性能(电阻率、载流子浓度和迁移率)和光学性能(可见光透射率、反射率和绒度)、表面形貌的影响,研究结果如下：(1)优化AZO薄膜的制备工艺参数。实验得出：当氧气和氩气流量比为0.007：1,工作气压为0.5-0.6Pa,衬底温度在397-400℃,功率为225W,沉积时间为40min,能制备得到光电性能优良的AZO薄膜,其电阻率为5-9×10-4Ω·cm,可见光平均透射率约为83%。(2)采用三种不同的腐蚀溶液用湿法刻蚀法对平面AZO薄膜进行刻蚀。实验得出：采用0.5%的稀盐酸溶液中加入一定量的醋酸对平面AZO薄膜腐蚀能获得形貌最好的、绒面比较均匀的绒面AZO薄膜。(3)采用不同配比的稀盐酸与醋酸混合酸液对AZO薄膜进行刻蚀。实验得出：当腐蚀溶液中醋酸与盐酸体积比为0.5：1时,能获得有较大绒度值的绒面。(4)采用0.5%稀HCl溶液中加入一定体积的醋酸(醋酸与浓盐酸体积比为0.5：1)配成混合酸液对AZO薄膜腐蚀不同时间。实验得出：腐蚀5s后,薄膜表面出现较小的均匀的“陨石坑”状的结构,随着腐蚀时间的变长,坑的大小在变大,当腐蚀时间为55s时,坑变得大了很多,并且坑状结构变得不均匀。(5)对低反应气压和高反应气压下制备的AZO薄膜腐蚀相同时间。实验得出：反应气压较低时,薄膜致密性较好,经腐蚀后薄膜具有较好的表面形貌。反应气压较高时,薄膜与衬底的附着力较差,表面点缺陷较多,分布也不均匀,腐蚀后获得的绒面不均匀。(6)用0.5%HCl溶液和稀HCl溶液浓度分别为0.5%、0.4%、0.3%加入相同体积醋酸(体积比为0.5：1)对AZO薄膜腐蚀5s、15s、25s、35s、45s、55s、65s。实验得出：0.5%HCl溶液加入醋酸后腐蚀45s能获得更大陷光结构的绒面。(7)用0.5%HCl溶液在不同HAc与HCl体积比下的腐蚀溶液腐蚀AZO薄膜相同时间15s、35s,测试两次反应后薄膜的厚度,计算薄膜的表面反应速率。实验得出：随着所加醋酸体积的的增加,腐蚀速率在逐渐变小,当醋酸与浓盐酸体积比为0.5：1,腐蚀速率最小,再增加醋酸的体积,腐蚀速率又开始变大。加入少量醋酸时,醋酸分子以氢键缔合为环状的双分子,其空间位阻作用使反应速率减慢；当再增加醋酸的含量,随着醋酸含量的增加,H+浓度也增大,又显著地加快了反应速率。更多还原

【Abstract】 Al-doped zinc oxide (AZO) transparent conductive film has low resistivity and high visible light transmittance, and textured structure can effectively reduce light reflection, increase the absorption of light and improve the conversion efficiency of solar cells,So it is widely applied to former electrode of thin film solar cells. It is extremely important to prepare the textured AZO thin film which has good photoelectric properties, higher haze and more uniform surface morphology for being applied to thin film solar cells, reducing the solar cell production costs and achieving large-scale industrialization production.For the time bing, the AZO thin film prepared by magnetron sputtering technique was etched by the 0.5% dilute HCl and could obtain excellent surface texture; but it is generally much difficult to gain the textured AZO thin film which has higher haze and more uniform textured structure in large area. So,it has very important significance to solve the problem for its application widely.In this paper, AZO thin film was etched by the mixed etching solution made by adding a certain amount of acetic acid into the dilute HCl. The affects on photoelectric properties, surface texture uniformity and reaction mechanism of AZO thin film was investigated after adding acetic acid, expecting to have certain directive significance for the uniformity of textured structure in large area.In this paper,the transparent conductive AZO thin films were deposited on glass substrate by DC-magnetron sputtering from ZnO/Al2O3 ceramic target doped 2wt.% Al2O3, and the textured AZO films were prepared by wet etching method.The affect of deposition parameters and etchant solution on electrical and optical properties of the textured AZO films was investigated systematically by four point probe, HMS-3000 Hall effect measurement system,UV-VIS-IR spectrophotometry and scanning electron microscopy(SEM),respectively.The results indicate:(1) Optimize the preparation technological parameters of AZO thin film.The results showed that the AZO thin films which had good photoelectric properties were prepared when O2 and Ar gas flow ratio was 0.007:1,air pressure was 0.5～0.6Pa,reaction temperture was 397～400℃, sputtering power was 225W and deposition time was 40min.the resistivity of he AZO thin films was up 5～9×10-4Ω·cm and the visible light transmittance was about 83%.(2) AZO thin films were etched by three etching solutions. The results showed that the textured AZO thin films having the best surface morphology and more uniform textured structure were gained when AZO thin films were etched by the mixed etching solution made by adding a certain amount of acetic acid into the 0.5% dilute HCl.(3) AZO thin films were etched by the mixed etching solution made by adding different volume of acetic acid into the dilute HCl.The results showed that the textured AZO thin films having higher haze were gained when the volume ratio of added acetic acid to 0.5% dilute HCl was 0.5:1.(4) AZO thin films were etched with different textured time by the mixed etching solution when the volume ratio of added acetic acid to 0.5% dilute HCl was 0.5:1.The results showed that AZO thin films can obtain uniform ’crater’ shape textured structure when etching time is 5s; the size of the crater becone bigger when AZO thin films were etched longer time and textured structure become more non-uniform when when etching time is 55s.(5)AZO thin films were etched with same textured time at different air pressure.The results showed that AZO thin films have good density and can gain good surface topography after textured when air pressure is lower,and the film adhesion is pooer and has more point defect at higher air pressure,so textured structure is non-uniform.(6) AZO thin films were etched by 0.5% dilute HCl and by the mixed etching solution made by adding a certain volume of acetic acid into the0.5%,0.4%,0.3% dilute HCl,respectively.The results showed that the textured AZO thin films having higher haze were gained when the volume ratio of added acetic acid to 0.5% dilute HCl was 0.5:1,and etching time is 45s.(7) AZO thin films were etched 15s or 35s by the mixed etching solution made by adding different volume of acetic acid into the dilute HCl,respectively. Testing film thickness, and then calculating the corrosion rate. The results showed that the corrosion rate become smaller in gradually with the increase of acetic volume, and the corrosion rate was minimum when the volume ratio of added acetic acid to 0.5% dilute HCl was 0.5:1;but the corrosion rate begun to get bigger when we continued to increase the volume of acetic acid. The acetic acid molecules associated with hydrogen for ring of double molecules,and its strric hindrance made reaction rate slower adding a little acetic acid.But continuing to add acetic acid,the concentration of H+ also increased along with the increase of acetic acid and accelerated the reaction rate significantly.更多还原