SBIR Phase II: Low Cost Copper Contacts with Built in Barriers for Crystalline Silicon Solar Cells

该小型企业创新研究第二阶段项目旨在开发用于硅太阳能电池金属化的铜基浆料。光伏（PV）为清洁和负担得起的能源提供了机会，在过去十年中，光伏行业的年复合增长率超过50%。虽然收入很高，但许多制造商的利润率大幅下降，因此需要在整个价值链中削减开支。降低成本的一个领域是太阳能电池的金属化，目前占世界供应量的近10%。光伏板的成本与价格波动的贵金属挂钩，可能导致可再生能源价格上涨;因此，用铜取代银对该行业来说是一个重大机遇。因此，该项目的成果将是使太阳能更便宜的产品。该项目还包括在肯塔基州创建两个新的全职职位，从事高级研究和制造。该提案将提高对铜-硅接触形成和材料在操作期间的耐久性的科学理解。在第一阶段，在标准和双面太阳能电池上证明了具有固有扩散阻挡层的铜浆的技术可行性。第二阶段将进一步改善丝网印刷浆料的行业标准。为了实现该市场所需的高电气性能，该项目将研究铜-硅界面，以研究接触形成过程中涉及的机制以及铜-硅界面的化学性质。这些信息将用于优化浆料的化学成分和热处理，以提高电性能和电池寿命。这些浆料将针对工业操作设备进行优化，为制造商提供一种可以直接使用的产品，同时对生产线的改动最小。第二阶段还将涉及扩大浆料中的核心材料，以便能够让客户参与进一步的印刷试验。通过原型太阳能电池模块的组装和测试，将证明铜触点的耐用性。该提案的成果将是丝网印刷铜浆，可以直接替代银浆，从而提高太阳能电池制造商的利润率。

This Small Business Innovation Research Phase II project aims to develop copper based pastes for the metallization of silicon solar cells. Photovoltaics (PV) offer an opportunity for clean and affordable energy and over the past decade the PV industry has seen annual compound growth rates of over 50%. Although revenues are high, the profit margins for many manufacturers have substantially diminished, necessitating the need for cutbacks throughout the value chain. One area marked for cost reduction, is in the metallization of the solar cells, which now commands nearly 10 percent of the world's supply. Having the cost of photovoltaic panels tied to a precious metal with price volatility can lead to higher prices for renewable energy; thus replacing silver with copper is a significant opportunity for the industry. Thus the outcomes of this project would be a product for making solar energy more affordable. The project also includes creating two new full time positions in Kentucky in Advanced Research and Manufacturing. This proposal will enhance scientific understanding of the copper-silicon contact formation and durability of the material during operation. The technological feasibility of the copper pastes with an inherent diffusion barrier was demonstrated on standard and bifacial solar cells in Phase I. Phase II will further improve the screen printable pastes to industry standards. To achieve the high electrical performance required in this market, the project will investigate the copper-silicon interface to investigate the mechanisms involved during contact formation, and the chemical nature of the copper-silicon interface. This information will be used to optimize the chemical composition and thermal treatment of the pastes to improve electrical performance and cell lifetime. The pastes will be optimized for industrial operating equipment to provide the manufacturer with a product that can be dropped in, with minimal changes to the production line. Phase II will also involve scale up of the core materials in the pastes to be able to engage customers in further printing trials. Through the assembly and testing of prototype solar cell modules, the durability of the copper contacts will be demonstrated. The outcomes of this proposal will be screen printable copper pastes that can be direct drop in replacement for the silver pastes; thereby enhancing the profit margins of the solar cell manufacturer.