Assessing the stability of high performance solution processed small molecule solar cells
Assessing the stability of high performance solution processed small molecule solar cells
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DOI：
10.1016/j.solmat.2016.12.021
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发表时间：
2017-03-01
影响因子：
6.9
通讯作者：
McGehee, Michael D.
中科院分区：
文献类型：
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作者：
Cheacharoen, Rongrong;Mateker, William R.;McGehee, Michael D.
溶液处理的小分子富勒烯体异质结（SM BHJ）太阳能电池的功率转换效率（PCE）大于10%。然而，SM - BHJ太阳能电池的降解还没有得到很好的研究。本文首次报道了包括创纪录的SM BHJ太阳能电池在内的六种高性能分子在器件工作条件下的稳定性研究。太阳能电池供体分子量范围从1200到2300 Da，给出6-10% PCE，在氮气中进行监测，在1个太阳照射下进行最大功率点跟踪，以及在25摄氏度和70摄氏度的黑暗中进行监测。热和光都会导致初始指数衰减或老化，总效率从31%降低到66%。较大的分子被发现可以抵抗热诱导老化，而更多的晶体活性层更能抵抗光诱导老化。在磨损后，观察到线性退化是由热过程控制的。SM BHJ太阳能电池的稳定TS80寿命范围从3450小时到5600小时。更高稳定性的分子设计应以提高热稳定性为目标，同时保持结晶度和光稳定性。
Solution-processed small molecule-fullerene bulk heterojunction (SM BHJ) solar cells now have power conversion efficiency (PCE) greater than 10%. However, degradation of SM BHJ solar cells has not been well studied. This work reports the first stability study of six high performance molecules including the record SM BHJ solar cells under device operating conditions. Solar cells with a range of donor molecular weight from 1200 to 2300 Da giving 6-10% PCE are monitored in nitrogen gas under 1 sun illumination with maximum power point tracking as well as at 25 degrees C and 70 degrees C in the dark. Both heat and light contribute to initial exponential decay or burn-in with total reduction in efficiency from 31% to 66%. Larger molecules are found to be resistant to heat induced burn-in, while more crystalline active layers are more resistant to light induced burn-in. After burn-in, the linear degradation is observed to be governed by thermal processes. Stabilized TS80 lifetimes of the SM BHJ solar cells range from 3450 h to 5600 h. Molecular design towards higher stability should aim at increasing thermal stability while maintaining crystallinity for photostability.