Si掺杂4,7-二(2-噻吩基)苯并噻二唑-3-辛基噻吩二炔在SnO2(100)表面吸附的理论研究

摘要

采用密度泛函理论与周期性平板模型相结合的方法,在GGA/PW91/DNP水平上研究了4,7-二(2-噻吩基)苯并噻二唑-3-辛基噻吩二炔(简称PTE-DTBT)和Si掺杂4,7-二(2-噻吩基)苯并噻二唑-3-辛基噻吩二炔(简称PTE-DTBT-Si)在SnO2(100)表面的吸附.通过吸附前后化合物PTE-DT-BT和PTE-DTBT-Si的Mulliken charge和前线轨道分析表明:当PTE-DTBT和PTE-DTBT-Si吸附在SnO2(100)表面时,PTE-DTBT向SnO2(100)表面转移了0.059 e电荷,SnO2(100)表面向PTE-DTBT-Si转移0.042 e电荷;同时前线轨道能隙变窄.通过吸附前后SnO2 (100)表面的能带和态密度分析表明:在SnO2 (100)表面吸附了化合物PTE-DTBT和PTE-DTBT-Si后,SnO2中价带和导带间的禁带变窄或消失.且研究表明,PTE-DTBT掺杂一个Si原子后,电池材料光伏性更好.%The density functional theory and periodic slab model at the GGA/PW91/DNP level are used to investigate the 3-octylthien-2,5-ylenediethynylene-co-benzo [c]-1',2',5'-thiadiazo-3,6-ylenedi (2,5 -thienylene) (PTE-DTBT for short) and silicon doping 3-octylthien-2,5-ylenediethynylene-co-benzo [c]-1',2',5'-thiadiazo-3,6-ylenedi (2,5-thienylene) (PTE-DTBT-Si for short) adsorption on SnO2 (100) Surface.The Mulliken charges and frontier orbitals of the PTE-DTBT and the PTE-DTBT-Si are also discussed.The results reveal that the charge of 0.059 e transfers from the PTE-DTBT to the SnO2 (100) surface,on the contrary,the charge of 0.042 e transfers from the SnO2 (100) surface to the PTE-DTBT-Si and the energy gap becomes narrow when the adsorption has occurred.The energy band structures and densities of states of the SnO2(100)-PTE-DTBT and the SnO2(100)-PTE-DTBT-Si are also discussed.The results reveal that the band gap becomes narrow or disappears when the adsorption has occurred.The results indicate that FTE-DTBT-Si has better activity of photovohaic than PTE-DTBT.