NOVA-Cell - Non Vacuum deposition & metallisation of CIGS solar cells

NOVA-Cell将利用硫属化物薄膜光致发光技术的潜力，开发和扩大新工艺，生产与大规模生产兼容的低成本高效太阳能电池。目前最先进的薄膜PV技术由碲化镉（CdTe）、无定形二氧化硅（a-Si）和铜-铟-镓-硒（CIGS）太阳能电池主导。由于有毒镉的存在和高成本碲的稀缺，CdTe的应用和商业化受到限制。非晶硅薄膜是最成熟的薄膜技术，这表明效率的提高将仅仅是渐进的。可商购获得的CIGS电池使用物理气相沉积（PVD）和Ag浆料的丝网印刷来制造。PVD在大面积上表现出有限的沉积均匀性，需要昂贵的基于真空的资本设备，并且当PVD靶被侵蚀时表现出工艺漂移。传统的丝网印刷技术限制了电极印刷的分辨率，并且银膏通常是纳米Cu价格的2-3倍，并且由于银的商品交易而受到相当大的价格波动。NOVA-Cell的主要目标是探索和评估CIGS薄膜太阳能电池制造新方法的技术可行性。将解决的方法包括通过新型非真空技术（CASVD）以低成本高效率沉积CIGS太阳能电池，以及使用高分辨率印刷技术（ESJET）沉积纳米铜金属电极结构，以将电池成本/瓦特降低10.6%，并减少遮光损失（代表0.6%的电池效率增益）。我们的方法是：（1）通过控制其组分的比例来优化CIGS吸收剂材料，以获得所需的化学组成;（2）通过控制沉积速率和温度来优化CIGS结构性质;（3）进行稳健的实验设计以优化中间硒化步骤以增加太阳能电池的吸收率，包括硒压力、温度和硒化时间;（4）进行传输线模型沉积测量，以修改ESJET沉积Cu金属化的接触和薄层电阻;（5）在CIGS上存款Cu电极结构;（6）进行初始效率和加速寿命测量。工作计划详见附录B，总结如下：WP 1：管理[M1-M12，PVI]，WP 2：开发和传播[M1-M12，PVI]，WP 3 CSAVD CIGS沉积[M2-M11，UCL]，WP 4：ESJET Cu金属化研究[M2-M11，PVI] WP 5：电池测试和加速寿命测量[M6-M12，UCL]。

NOVA-Cell will exploit the potential of chalcogenide-based thin film photovoltaics technology for the development and scale up of new processes for the production of low cost efficient solar cells compatible with mass production. Current state of the art thin film PV technology is dominated by cadmium-tellurim (CdTe), amorphous silica (a-Si) and copper-indium-gallium-selenide (CIGS) solar cells. The application and commercialisation of CdTe is limited due to the presence of toxic cadmium and the scarcity of high-cost tellurium. Amorphous silicon thin film is the most mature of thin filmtechnologies, suggesting that efficiency gains will be merely incremental. Commercially available CIGS cells are manufactured using physical vapor deposition (PVD) and screen printing of Ag pastes. PVD exhibits limited uniformity of deposition across large areas, requires expensive vacuum based capital equipment and exhibits process drift as the PVD targets are eroded. Conventional screen printing techniques limit the resolution of electrode printing, and silver pastes are typically 2-3 x the price of nano-Cu and subject to considerable price volatility due to the commodity trading of silver. NOVA-Cell's main objective is to explore and evaluate the technical feasibility of novel methods for the manufacture of CIGS thin film solar cells. The methods that will be addressed include the deposition of CIGS solar cells via a novel nonvacuumtechnology (CASVD) with high-efficiency at low cost, and the deposition of nano copper metallic electrode structures using high-resolution printing technology (ESJET) to reduce cell cost/Watt by 10.6%, and to reduce shading losses (representing a 0.6% cell efficiency gain).Our approach will be:(1) to optimise the CIGS absorber material by controlling ratio of its components to obtain the desired chemical composition;(2) to optimise the CIGS structural properties through control of the deposition rate and temperature;(3) to conduct a robust design of experiments to optimise the intermediate selenisation step for increased absorbance of the solar cell, including the selenium pressure, the temperature and the selenisation time; (4) to conduct transmission line model deposition measurements to modify the contact and sheet resistance of the ESJET deposited Cu metalisation;(5) to deposit Cu electrode structures onto CIGS;(6) to conduct initial efficiency and accelerated lifetime measurements.The work programme is detailed in Appendix B and is summarised below: WP1: Management [M1-M12, PVI], WP2:Exploitation and Dissemination [M1-M12, PVI], WP3 CSAVD CIGS deposition [M2-M11, UCL], WP4: ESJET Cu metallisation study [M2-M11, PVI] WP5: Cell Testing and accelerated lifetime measurements [M6-M12, UCL].