基于n型晶体硅衬底的宽禁带窗口层异质结太阳电池的前端电极设计机理与实验研究

项目名称： 基于n型晶体硅衬底的宽禁带窗口层异质结太阳电池的前端电极设计机理与实验研究

项目编号： No.51302028

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 一般工业技术

项目作者： 周海平

作者单位： 电子科技大学

项目金额： 25万元

中文摘要： 硅基异质结电池结合了常规晶体硅电池高转化效率、高稳定性与非晶硅薄膜电池低温生长工艺的优点，是当今太阳电池研究的一个热点。通常的硅异质结电池采用非晶硅或微晶硅发射层，由于其禁带宽度的限制，存在较大的寄生吸收损失，限制了电池光生电流的提高。本项目提出了基于PECVD方法生长的氧化硅薄膜作为异质结电池窗口层以减少电池在可见光波段的寄生吸收损失，进而提高电池能量转化效率的方案。对基于n型晶体硅的异质结电池，为了降低p型宽禁带窗口层与n型透明导电薄膜之间功函数失配导致的肖特基势垒，采用界面镶嵌高功函数的金纳米颗粒以便在两者之间形成欧姆接触。与此同时，处于前电极的金纳米颗粒还可形成有效的表面等离子激元，凭借局域的共振吸收效应进一步减少电池表面光损失。结合电池光伏性能测试，实现面向器件的、可控的纳米金颗粒生长，最终在宽禁带异质结电池中达到光学吸收与电学输运的双重提升。

中文关键词： 异质结太阳电池；宽禁带窗口层；表面等离激元；高密度等离子体；等离子处理

英文摘要： Si-based heterojunction solar cell, which combines the advantage of high energy conversion efficiency and high stability for crystalline silicon solar cells, with the advantage of low-temperature process for thin film solar cells, is one of the word-wide research focuses. The a-Si:H based emitter in a conventional heterojunction solar cell has a considerable parasitic absorption in the visible spectrum region, which severely limits the photo-generated current due to a comparatively lower optical bandgap. In the present proposal, a wide bandgap material, PECVD-grown SiOx:H is proposed to be the window layer in n-type crystalline Si based heterojunction solar cells for reducing the parasitic absorption. In order to eliminate the intrinsic Shockley barrier height beween the p-SiOx:H window layer and the n-ZnO:Al TCO layer due to the considerable work function mismatch, high work function metal of Au nanoparticles are embedded in the interface of them to form a ohmic contact. Simultaneously, the embedded Au nanoparticles can form a surface plasmon resonance to suppress the reflected light loss on the solar cell surface. The morphology, size and its distribution, thickness and coverage of the Au nanoparticles, which collectively influence the photovoltaic performance of the resultant solar cell, will be optimized acc

英文关键词： Heterojunction solar cells；wide-bandgap window；Surface plasmon；High-density plasma；Plasma processing