利用氢化非晶硅薄膜和氧化银纳米颗粒改善掺钕钛酸铋铁电薄膜的光伏效应研究

项目名称： 利用氢化非晶硅薄膜和氧化银纳米颗粒改善掺钕钛酸铋铁电薄膜的光伏效应研究

项目编号： No.51272166

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 一般工业技术

项目作者： 郑分刚

作者单位： 苏州大学

项目金额： 80万元

中文摘要： 与pn结的内建电场相比，铁电薄膜中剩余极化排列取向形成的内建电场贯穿整个薄膜内部，从而获得巨大的开路电压（15V）；该内建电场在外加电场的作用下能发生反转。然而，铁电薄膜具有较大的禁带宽度，无法吸收太阳光中大部分的可见光；传统电容器结构的铁电薄膜，具有"背靠背"界面肖特基势垒，导致光伏发电效率较低。本项目以掺钕钛酸铋（BNT）铁电薄膜为研究对象，在ITO/BNT/Ag结构中插入一层低禁带宽度（1.9eV）的氢化非晶硅薄膜（a-Si:H），形成ITO/BNT/a-Si:H/Ag结构。以ITO/BNT界面肖特基势垒和BNT薄膜剩余极化构成首尾相连的内建电场，a-Si:H/Ag之间形成欧姆接触（消除BNT/Ag界面肖特基势垒），并利用a-Si:H薄膜吸收短波长可见光；在BNT薄膜内部包裹禁带宽度1.2eV的氧化银纳米颗粒，吸收长波长可见光。本项目致力于研究铁电薄膜光伏效应机制，提高光伏发电效率。

中文关键词： 铁电薄膜；光伏效应；非晶硅薄膜；表面等离激元；

英文摘要： Compared with the built-in field of pn junction, the field of ferroelectric film due to the aligned remnant polarizaiton exists in the whole film, which can lead to huge open-circuit photovoltage (15V) and be swicthed under the external poling field. However, ferroelectric films can not absorb the visual light of the sunlight due to their large band gaps. Furthermore, in the electrode/ferroelectric-film/electrode capacitor, there are a pare of "back-to-back" Schottky barriers at top and bottom film/electrodes, which can result in a low photovoltaic efficience. In this project, Nd doped bismuth titanate ferroelectric film (BNT) is selected as the object of study. In ITO/BNT/Ag capacitor, an amorphous hydrogenate sillicon film (a-Si:H) with low band gap (about 1.9 eV) will be inserted between BNT and Ag formimg the ITO/BNT/a-Si:H/Ag structure, in which the direction of the filed due to the aligned remnant polarization can be modulated to that of the field of ITO/BNT interface Schottky barrier. The inserting of a-Si:H could eliminate the Schottky barrier of BNT/Ag interface because the contact between a-Si:H and Ag is ohmic, and a-Si:H can absorb shorter wavelength visual light of the sunlight. Furthermore, nano particals of silver oxide (Ag2O) with 1.2 eV band gap introduced into the center of BNT film could absor

英文关键词： ferroelectric film；photovoltaic；amorphous silicon；surface plamons；