Managing BHJ microstructural evolution for long-term photoconversion efficiency (Conference Presentation)
Managing BHJ microstructural evolution for long-term photoconversion efficiency (Conference Presentation)
复制标题
管理 BHJ 微结构演化以实现长期光转换效率（会议演示）
DOI：
10.1117/12.2238167
复制
发表时间：
2016
期刊：
影响因子：
--
通讯作者：
Martinez Hardigree J
中科院分区：
文献类型：
--
作者：
Martinez Hardigree J
在本报告中，我们评估的热和光浸泡稳定性的聚合物：富勒烯体异质结（BHJ）的基础上，最近开发的默克化学品的供体聚合物。采用原子力显微镜（AFM）、掠入射X射线衍射（GIXD）、中子反射率（NR）和紫外-可见光谱法研究了纯聚合物和BHJ结合PC61 BM或PC 71 BM的刀片涂层薄膜。以与器件相关的浓度（25- 50重量%）将富勒烯添加到聚合物中导致相对于纯聚合物膜的表面粗糙度降低7倍，这归因于随着聚合物：富勒烯混合越来越均匀，纯聚合物域尺寸减小。经受与可扩展的OPV制造相关的加速应力的膜-在120 °C下热应力1小时或在AM 1.5光下光浸泡8小时-表明对应力的稳健稳定性，其中薄膜显示出粗糙度随着富勒烯浓度的增加而轻微但单调地增加。广角GIXD测量表明，在退火时归因于聚合物结晶域的特征收缩1-4%。退火前和退火后的膜的比较揭示了在后者中的聚合物散射特征之间的相关性增加，与聚合物主链和侧链的改进的有序性一致。这些发现，连同GIXD测量的完整设备堆栈和加速老化测量的操作电池，支持最近的报告，这种聚合物BHJ系统的高光电转换效率的稳定性，高度可扩展的，长寿命的OPV。
In this presentation we evaluate the thermal and light-soaking stability of polymer:fullerene bulk heterojunctions (BHJs) based on a donor polymer recently developed by Merck Chemicals. Blade-coated thin films of pure polymer and BHJs incorporating either PC61BM or PC71BM were investigated using atomic force microscopy (AFM), grazing-incidence x-ray diffraction (GIXD), neutron reflectivity (NR), and UV-Visible spectroscopy. The addition of fullerene to the polymer at device-relevant concentrations (25-50% by weight) results in a 7-fold reduction in surface roughness relative to pure polymer films, attributed to a reduction in the pure polymer domain size with increasingly homogeneous polymer:fullerene mixing. Films subjected to accelerated stressing relevant to scalable OPV fabrication—thermal stressing at 120 °C for 1 hour or light-soaking under AM1.5 light for 8 hours—indicate robust stability to stressing, with thin films showing marginal but monotonic increases in roughness with increasing fullerene concentration. Wide-angle GIXD measurements indicate a contraction of 1-4% in features attributed to polymer crystalline domains upon annealing. Comparison of pre-and post-annealed films reveals increased correlation between polymer scattering features in the latter, consistent with improved ordering of the polymer backbone and sidechains. These findings, together with GIXD measurements of full device stacks and accelerated aging measurements of operational cells, support recent reports on the high photoconversion efficiency stability of this polymer BHJ system for highly scalable, long-lifetime OPVs.