掠角沉积新技术定向生长同轴径向硅纳米棒太阳电池

项目名称： 掠角沉积新技术定向生长同轴径向硅纳米棒太阳电池

项目编号： No.60806020

项目类型： 青年科学基金项目

立项/批准年度： 2009

项目学科： 金属学与金属工艺

项目作者： 刘丰珍

作者单位： 中国科学院大学

项目金额： 25万元

中文摘要： 新概念同轴纳米棒径向pn结太阳电池，克服了平面结构电池对光吸收和载流子收集难以兼顾的矛盾，将光吸收和电收集分离，有望采用低少子寿命的廉价材料获得高的转换效率。根据掠角沉积技术可制备定向生长、形状可控纳米棒的特点，根据热催化化学气相沉积技术无离子轰击、大量原子氢有利于晶化和保角沉积的特点，我们将掠角沉积与热催化化学气相沉积技术结合，来制备同轴硅纳米棒径向pn结太阳电池。通过优化系统结构参数和沉积参数，获得定向生长、晶化的硅纳米棒，研究硅纳米棒的掺杂特性和同轴生长，结合电池模拟计算，获得同轴硅纳米棒径向pn结太阳电池的原理性器件。期待能够在新概念高效率太阳电池的研究中开辟新路径。

中文关键词： 硅纳米棒;同轴径向pn结太阳电池;掠角沉积;热催化化学气相沉积

英文摘要： Low diffusion semiconductor materials as the absorbing base in a planar pn junction solar cell geometry result in carrier collection limition due to the high defect density in the materials. The new concept coaxial pn junction nanorod solar cells, with a pn junction in the radial direction of the nanorods, allow for separation of the requirements of light absorption and carrier extraction in two orthogonal directions. This proved the possibility to achieve solar cell with high efficiency by using inexpensive materials. Glancing angle deposition (GLAD), based on deposition with obliquely incident flux and the atomic-scale shadowing effect, is a promising nanorods deposition technique.The materials with isolated nano-columnar structure can be designed and sculpted by adjusting the oblique angle and the rotation of the substrate. Hot wire chemical deposition (HWCVD) has the characteristics of high deposition rate, ion-free, abundant atomic H, conformal deposition and low temperature crystallization and has been widely adopted in the micro-crystalline silicon deposition. Considering the advantages of the two techniques,in this project, we combine the HWCVD with GLAD for the first time to produce silicon nanorods and silicon coaxial pn junction solar cells. The system and deposition parameters, including instrument structure, deposition pressure, gas flow rate, H dilution ratio, gas phase doping, conformal cover deposition will be systematically investigated to obtain the crystallized vertical silicon nanorods and radial pn junction at low temperature. Assisted by the theoretic simulation of the solar cell, the prototype silicon coaxial pn junction nanorod solar cells will be achieved.

英文关键词： Si nanorod；radial pn junction solar cell;GLAD;HWCVD