Lifetime and encapsulation study of organic solar cells (LEOsc)

有机太阳能电池（LEOsc）的寿命和封装研究

• 批准号: EP/X036014/1
• 负责人: Yuanyuan Cao
• 金额: $ 64.93万
• 依托单位: University of Oxford
• 依托单位国家: 英国
• 项目类别: Fellowship
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FX036014%2F1
• 关键词: Lifetime; encapsulation; study; organic; solar

The Paris Agreement set the goal to reach Net-Zero emission by 2050 to tackle global warming; this has stimulated much research into energy transition. Photovoltaic technology receives great attention as it can meet increasing energy demands by converting solar radiation into electricity without greenhouse gas emissions. However, global PV deployment is still low (only 5% of global electricity came from PV technology in 2021) and the market is currently dominated by energy-intensive conventional crystalline silicon PV. To facilitate the energy transition, novel photovoltaic technologies, such as organic solar cells (OSCs), are being intensively studied for flexible & lightweight applications. However, OSCs must fulfil requirements in efficiency, lifetime, and cost for future commercialisation. The cost of OSC production and installation is expected to be very low compared to conventional Si. Continuing developments have been made in improving OSC efficiency and indeed competitive high PCE (power conversion efficiency) of about 20% has been reached so far. While OSC lifetime is still substantially lower than that of inorganic cells and there is much room for improvement. Since OSC degradation is mainly caused by exposure to moisture and oxygen, encapsulation of the cells is one of the most straightforward ways to improve OSC life expectancy. In this context, this Fellowship research focusses on the OSC lifetime study. The proposed tasks involve two aspects, encapsulation layer development and OSC extrinsic degradation mechanism study.Specifically, the atomic layer deposition (ALD) technique will be utilized for the fabrication of the encapsulation layer. ALD is a technique based on the self-limiting reaction between distinct precursors, which can deposit dense thin films with excellent uniformity. The uniformity of the film allows the water and oxygen permeation rate to be extremely low, thus the encapsulation film can protect OSCs longer. The Fellowship will systematically investigate all the encapsulation strategies by the ALD technique, namely: (1) Barrier films for lamination. This strategy allows the possibility of manufacturing the barrier films in advance, then OSCs will be laminated with barrier films. A huge advantage of this scheme is the whole processing of a module can be done in a roll-to-roll configuration and the ALD conditions are not limited by the sensitive organics. (2) Direct thin-film encapsulation (TFE). This strategy is desirable to minimize mechanical stress, abrasion to the barrier, and device contamination. The main issue of TFE is the encapsulation processing conditions are highly constrained by the organics. In both strategies, OSC encapsulation layers with low moisture permeation and sufficient mechanical durability will be developed, an intermediate layer will also be developed to serve as a better growth surface for ALD materials to ensure the thin films are perfect. The deposition rate will be improved to increase the production throughput of ALD. Comparisons of the encapsulation performance within the different strategies will address the best encapsulation configuration for OSCs. Thereafter, the optimal encapsulation will be utilised for the protection of state-of-the-art OSCs, accelerated tests and outdoor lifetime tests will be performed on the protected OSCs to characterise the lifetime. The extrinsic degradation of encapsulated cells will be also studied to address the cell break-down. Optimisation strategies will be given to the encapsulation layers according to the degradation mechanism. My goal is to push the lifetime of the OSC to a comparable level to that of Si. At the end of the Fellowship, scale-up trials will be undertaken with the help of Oxford Physics' Innovation and Enterprise Manager (Phillip Tait) and our industry partners.

《巴黎协定》设定了到2050年实现净零排放的目标，以应对全球变暖，这激发了许多关于能源转型的研究。光伏技术受到极大关注，因为它可以通过将太阳辐射转化为电力而不排放温室气体来满足日益增长的能源需求。然而，全球光伏部署仍然较低（2021年仅5%的全球电力来自光伏技术），市场目前由能源密集型常规晶硅光伏主导。为了促进能源转型，人们正在深入研究有机太阳能电池（OSC）等新型光伏技术，以实现灵活且轻质的应用。然而，OSC必须满足未来商业化的效率，寿命和成本要求。OSC的生产和安装成本预计将非常低，相比传统的硅。在提高OSC效率方面已经取得了持续的发展，并且到目前为止已经达到了大约20%的具有竞争力的高PCE（功率转换效率）。虽然OSC寿命仍然大大低于无机电池的寿命，并且存在很大的改进空间。由于OSC降解主要是由暴露于水分和氧气引起的，因此细胞的封装是提高OSC预期寿命的最直接方法之一。在这种情况下，该奖学金的研究重点是OSC的寿命研究。本研究的主要工作包括封装层的研制和OSC非本征退化机理的研究两个方面，具体而言，封装层的制备将采用原子层沉积（ALD）技术。ALD是一种基于不同前体之间的自限制反应的技术，其可以沉积具有优异均匀性的存款致密薄膜。薄膜的均匀性使得水和氧气的渗透率极低，因此封装膜可以更长时间地保护OSC。该研究员将系统地研究ALD技术的所有封装策略，即：（1）用于层压的阻挡膜。这种策略允许提前制造阻隔膜的可能性，然后将OSC与阻隔膜层压。该方案的一个巨大优点是模块的整个处理可以在卷对卷配置中完成，并且ALD条件不受敏感有机物的限制。(2)直接薄膜封装（TFE）。该策略是期望的，以最小化机械应力、对屏障的磨损和装置污染。TFE的主要问题是封装工艺条件受到有机物的高度限制。在这两种策略中，将开发具有低水分渗透和足够机械耐久性的OSC封装层，还将开发中间层以作为ALD材料的更好生长表面，以确保薄膜是完美的。沉积速率将被改善以增加ALD的生产吞吐量。不同策略内的封装性能的比较将解决OSC的最佳封装配置。此后，将利用最佳封装来保护最先进的OSC，将对受保护的OSC进行加速测试和户外寿命测试，以延长寿命。还将研究包封细胞的外在降解，以解决细胞分解问题。根据退化机理给出了封装层的优化策略。我的目标是将OSC的寿命推到与Si相当的水平。在奖学金结束时，将在牛津物理的创新和企业经理（菲利普泰特）和我们的行业合作伙伴的帮助下进行扩大试验。