Recently, the State Key Laboratory of High Field Laser Physics of SIOM, CAS, has made progress in ultrafast dynamics of polymer solar cells (PSCs) with Soochow University. The research team used femtosecond transient absorption technology to study active layer of organic solar cells, explaining the contribution of DIO additives to the efficiency enhancement of PSCs. The results are published in Nanomaterials on 30 October, 2020.

As a new type of solar cell device, PSCs have the advantages of light weight, mechanical flexibility and low-cost fabrication. But low efficiency is the main limit of its large-scale application.

The research team studied the effect of DIO additives on photocarrier generation in donor materials (P51) and bulk heterojunction films (P51:PC71BM) by pump-probe measurement.

Researchers found that the introduction of DIO additives can improve the lifetime of polaron pairs in the P51, which is beneficial to the photocarrier generation. Moreover, in bulk heterojunction films (P51:PC71BM), DIO additives can promote free charge generation as well as Charge Transfer (CT) excitons generation and separation.

From the aspect of ultrafast dynamics, these results reveal the effect of DIO on carrier generation and separation, providing an effective route to improve the efficiency of nanoscale polymer solar cells.

This work was funded by National Key R&D Program of China; Strategic Priority Research Program of the Chinese Academy of Sciences; Shanghai Municipal Science and Technology Major Project; National Natural Science Foundation of China.

Figure. A schematic of ultrafast interfacial excitons dynamics in the P51:PC71BM blend after photoexcitation. (Image by SIOM)

Article website:
https://doi.org/10.3390/nano10112174

Contact:
WU Xiufeng
General Administrative Office
Shanghai Institute of Optics and Fine Mechanics, CAS
Email: xfwu@siom.ac.cn
Web: http://english.siom.cas.cn/