CdTe薄膜太阳能电池

1、CdTe薄膜太阳能电池,一、CdTe薄膜太阳能电池原理 二、CdTe薄膜太阳能电池结构 三、TiO2作缓冲层文献分析 四、CdTe太阳能电池展望 五、参考文献,CdTe太阳能电池的原理,光子的能量公式,可见光的波长：380760nm 能量：1.643.19eV,CdTe的能隙值为1.45eV，是直接能隙。,TCO的能隙为3.24.3eV，是间接能隙。,CdTe太阳能电池的结构类型,由于Substrate型太阳能电池CdS/CdTe的界面品质较差，欧姆接触性差， 所以转化效率较低，一般不常用。,CdTe太阳能电池结构图,降低CdTe与金属 电极接触势垒,P型半导体,N型半导体,透明导电氧化层,玻

2、璃衬底,一般选用钙钠玻璃作为太阳能电池的衬底，主要起支架、防止污染和太阳光入射的作用。,TCO 透明导电氧化层,CdS窗口层,1、CdS的能隙一般在2.4eV，几乎所有的可见光都能透过。 2、CdS层与CdTe层形成p-n结。 3、为了使太阳能电池获得更高的效率，CdS层要尽量的薄， 一般在不超过500nm,1、CdTe能隙值为1.45eV,位于理想的太阳能电池的能隙之 间，且具有很高的吸光系数，是非常理想的光伏材料 2、CdTe层的厚度一般在2-8m.,CdTe吸收层,背接触层和背电极,降低CdTe和金属电极的接触势垒，引出电流，是金属电极与CdTe形成欧姆接触,Performance im

3、provement of solution-processed CdS/CdTe solar cells with a thin compact TiO2 buffer layer,Question,In order to reduce the light absorption loss in CdS, the CdS thickness is usually less than 500 nm. However, pinholes in CdS and non-conformal coverage of CdS on transparent conducting oxide layer wil

4、l cause shunting thus leading to device performance degradation and failure.,Solution,In order to alleviate this problem , a layer of TiO2 was inserted between the FTO and CdS as a buffer layer.,Materials and methods,1、Substrate cleaning (the soda-lime glasses coated with 600nm FTO) 2、TiO2 was depos

5、ited using DC magnetron sputtering 3、 CdS chemical bath deposition 4、CdTe electrochemical deposition 5、CdCl2 treatment （the wafe in CdCl2 methanol solution at 60 for 20 min) 6、50nm Au dots were deposited by thermal evaporation as back contact .,1、TiO2 in solar cells helps in improving efficiency by

6、stopping holes from going to TCO front contact . 2、TiO2 window layer helps in the separation of charge carriers and reduces the recombination rate.,In order to identify the optimum thickness for TiO2, solar cell devices with 20-, 40-, 60-, 80- and 100-nm-thick,Conclusions,1、By inserting a compact Ti

7、O2 layer with 20 nm thickness, device yield was improved to more than 80 % with a peak efficiency of 8.0 %. 2 、TiO2 buffer layer helps to solve the short-circuiting problems caused by thinnon-uniform CdS. The addition of a compact TiO2 layer was also found to significantly improve device stability.,CdTe太阳能电池发展前景,CdTe薄膜太阳能电池具有成本低，工艺制备简单，其吸收层与光谱最一致的优点， 是未来太阳能电池发展的方向,First Solar公司是全球最大的CdTe太阳能电池生产商，该致力于CdTe太阳