摘要
本文设计合成了2种基于螺二芴-苯并噻二唑骨架的新型有机小分子光伏给体材料SF(BT)_(2)和SF(aBT)_(2),并探究了其热稳定性、光吸收性质、电化学性质及光伏性能.在分子设计上,采用螺二芴作为中心给电子单元(D),苯并噻二唑衍生物作为端基吸电子单元(A),构筑了A-D-A型分子SF(BT)_(2).在此基础上引入乙炔基作为π桥,构筑A-π-D-π-A型分子SF(aBT)_(2).2种材料均具有较窄的能隙,分别为1.67和1.72 eV.其中,基于SF(BT)_(2)的光伏器件由于材料良好的光吸收及窄能隙特性显示出优异的光伏性能,获得了4.92%的能量转化效率以及14.88 mA·cm^(-2)的短路电流密度.
Two novel organic small molecule donor materials SF(BT)_(2)and SF(aBT)_(2)based on spirofluorene-benzothiadiazole framework were designed and synthesized successfully.This work provides a new molecular design approach to develop efficient small molecule donor materials.A-D-A molecule SF(BT)_(2)was constructed by using spirofluorene as the central electron-donating unit(D)and benzothiadiazole derivative as the terminal electron-withdrawing unit(A).On this basis,ethynyl group was introduced as theπbridge,and thus the A-π-D-π-A type molecule SF(aBT)_(2)was constructed.The energy level,dipole moment and optical absorption of the material were predicted by density functional theory and time-dependent density functional calculations.The thermal stability,light absorption,electrochemistry and photovoltaic properties of the two novel materials were investigated.Both SF(BT)_(2)and SF(aBT)_(2)possess narrow energy-gap of 1.67and 1.72eV,respectively.The introduction of the ethynyl asπbridge brings an important effect on the optical absorption of the material,which is related to the rigidity and the electron-withdrawing property of the ethynyl group.The photovoltaic device based on SF(aBT)_(2)/PC_(61)BM shows a relatively higher open circuit voltage compared to the device based on SF(BT)_(2)/PC_(61)BM.It is suggested that the introduction of ethynyl group provides the possibility to increase the open circuit voltage of the photovoltaic device.It is worth noting that the device based on SF(BT)_(2)/PC_(61)BM shows a power conversion efficiency of 4.92%and a short-circuit current density of 14.88mA·cm^(-2),due to its good light absorption and narrow energygap characteristics.The research implies that novel small molecule donor materials based on spirofluorene-benzothiadiazole framework have the potential to be donor materials with excellent performance.
作者
梁月亭
殷伦祥
李艳芹
LIANG Yue-ting;YIN Lun-xiang;LI Yan-qin(Chemical Engineering Institute,Dalian University of Technology,Dalian 116024,China)
出处
《分子科学学报》
CAS
北大核心
2022年第5期386-395,共10页
Journal of Molecular Science
基金
国家自然科学基金资助项目(21102013)
高校基本科研业务费重大专项资助项目(DUT16ZD205)。
关键词
有机小分子
有机光伏材料
螺二芴
苯并噻二唑
organic small molecule
organic photovoltaic materials
spirobifluorene
benzothiadiazole
