Effect of Annealing on Exciton Diffusion in a High Performance Small Molecule Organic Photovoltaic Material.
Effect of Annealing on Exciton Diffusion in a High Performance Small Molecule Organic Photovoltaic Material.
复制标题
DOI：
10.1021/acsami.6b16487
复制
发表时间：
2017-05-03
影响因子：
9.5
通讯作者：
Samuel IDW
中科院分区：
文献类型：
--
作者：
Long Y;Hedley GJ;Ruseckas A;Chowdhury M;Roland T;Serrano LA;Cooke G;Samuel IDW
研究了高效有机光伏电子给体材料FBTTh 2中的单重态激子扩散。三个互补的时间分辨荧光测量进行：淬火平面异质结与电子受体，激子-激子湮灭，和荧光去极化。平均激子扩散系数从1.6 × 10-3增加到3.6 × 10- 3cm ~ 2·s ~（-1），导致平均二维激子扩散长度（LD =（4Dτ）1/2）从15 nm增加到27 nm.大约30%的激子在铸态薄膜中很快被捕获。该材料的高激子扩散系数导致其能够从体异质结中的大施主域有效地收获激子。
Singlet exciton diffusion was studied in the efficient organic photovoltaic electron donor material DTS(FBTTh2)2. Three complementary time-resolved fluorescence measurements were performed: quenching in planar heterojunctions with an electron acceptor, exciton–exciton annihilation, and fluorescence depolarization. The average exciton diffusivity increases upon annealing from 1.6 × 10–3 to 3.6 × 10–3 cm2 s–1, resulting in an enhancement of the mean two-dimensional exciton diffusion length (LD = (4Dτ)1/2) from 15 to 27 nm. About 30% of the excitons get trapped very quickly in as-cast films. The high exciton diffusion coefficient of the material leads to it being able to harvest excitons efficiently from large donor domains in bulk heterojunctions.