Collaborative Proposal: Fundamental Research on Physics of Instability of Organic Solar Cells

项目负责人：Dalal， Vikram / Schiff， eric提案编号：1336134 / 1336147机构：爱荷华州立大学/雪城大学标题：合作提案：有机太阳能电池不稳定性物理基础研究该项目将系统地研究、识别并潜在地克服材料和设备中导致有机太阳能电池在光照下降解的各种物理现象。有机光伏（OPV）器件是一种日益重要的光伏（PV）能量转换技术。最近，单结和串联结OPV太阳能电池的效率达到了12%，这对于最终的商业应用来说是非常令人鼓舞的。然而，众所周知，当暴露在光下时，这些设备会迅速退化，即使被封装或保存在惰性环境中，在照明约100小时内也会损失20-30%的初始效率。该技术的主要市场是建筑集成产品，因为原则上，OPV设备可以层压在现有的窗框上。对于这样的商业部署，至关重要的是，在产品的生命周期内，将退化显著减少到10%的范围，对于构建产品来说，这通常是20年。同样，另一个主要的细分市场，为发展中国家的农村人口提供电力，也需要相对较长的寿命，尽管它们不需要与美国并网中央电力相同的电力转换效率。该项目将系统地研究基本物理参数的变化，如光吸收、空孔迁移率、当OPV材料和器件受到光照时，吸收材料和异质结界面处的深态密度。pi将使用电学测量（如不同温度下的电容频率）和结构测量（如自旋共振）来研究缺陷的演变。pi将研究在不同光强下缺陷随时间演变的动力学，从而建立控制缺陷演变的动力学规律。然后，pi将系统地探索这些缺陷随时间的热退火，从而找出退火的活化能。pi将这些动力学和退火能量与有机材料的结构，形态和组成以及用于制造设备的特定技术相关联。将研究许多不同的材料，如P3HT和pcdbt，并建立各种动力学参数与材料中键合性质之间的关系。我们将利用这些结果来设计和制造更好的聚合物，这些聚合物可能在保持功率转换效率的同时更稳定。更广泛的影响包括工作的工业影响，特别是在OPV器件和材料领域的研究生和本科生的教育，以及一般的太阳能转换装置。通过在现有课程中加入新的实验部分，将研究成果转移到教育中。女性和代表性不足的少数群体学生都有望在研究中发挥重要作用。研究结果将通过出版物和通过IEEE举办的网络研讨会广泛传播给科学家和工程师。将通过在美国和海外举行讲座的方式向国民进行宣传。

PI: Dalal, Vikram / Schiff, EricProposal Number: 1336134 / 1336147Institution: Iowa State University / Syracuse UniversityTitle: Collaborative Proposal: Fundamental Research on Physics of Instability of Organic Solar CellsThis project will to systematically study, identify, and potentially overcome the various physical phenomena in both materials and in devices that lead to degradation of organic solar cells when subjected to light. Organic photovoltaic (OPV) devices are an increasingly important photovoltaic (PV) energy conversion technology. Recent advances in efficiency to ~12% range in both single and tandem junction OPV solar cells are very encouraging for eventual commercial deployment. However, the devices are known to degrade rapidly when exposed to light, losing 20-30% of the initial efficiency within ~100 hours of illumination, even when encapsulated or kept in inert atmospheres. A major market for this technology is building-integrated products, since in principle, the OPV devices can be laminated onto existing window frames. For such commercial deployment, it is essential that the degradation be reduced significantly, to 10% range over the lifetime of the product, which is typically ~20 years for building products. Similarly, another major market segment, providing power for rural populations in developing countries, also requires relatively long life, even though they do not require the same power conversion efficiency as grid-connected central power in the U.S. This project will systematically investigate the changes in fundamental physical parameters such as optical absorption, hole mobility, deep state densities in both the absorber materials and at the hetero-junction interface when OPV materials and devices are subjected to illumination. The PIs will study the evolution of defects using both electrical measurements such as capacitance-frequency at different temperatures, and structural measurements such as spin resonance. PIs will study the kinetics of defect evolution over time under varying intensities of light so as to establish kinetic laws that govern defect evolution. Then, the PIs will systematically explore the thermal annealing of these defects over time, thereby finding out activation energies for annealing. The PIs will correlate these kinetics and annealing energies to the structure, morphology and composition of the organic materials, and the specific technology used for fabricating the devices. A number of different materials such as P3HT and PCDTBT will be studied and the relationship between the various kinetic parameters to the nature of the bonding in the materials will be established. We will use these results to design and fabricate better polymers which are likely to be more stable while maintaining power conversion efficiency. The broader impact consists of the industrial impact of the work, and in educating both graduate and undergraduate students in the field of OPV devices and materials in particular, and solar energy conversion devices in general. Significant attention will be paid to transfer the research results into education by including new lab sections in existing courses. Both women and under-represented minority group students are expected to play a significant role in the research. The results of the research will be broadly disseminated to scientists and engineers through publications, and by offering webinars through IEEE. Dissemination to the general public will be done by giving talks both in the U.S. and overseas.