一系列单硅烷-寡聚噻吩共聚高分子膜中电荷传导研究

Charge Transport Study of a Series of Monosilanylene-oligothienylene Copolymer Films

研究了一系列由单硅烷和寡聚噻吩组成的共聚高分子膜(PSnT,n表示寡聚噻吩单元中噻吩环的个数)在较宽掺杂率范围内载流子的迁移率变化规律.结果表明,掺杂率极低(<0·2%)时各膜中的载流子迁移率接近,几乎不受n的影响;随着膜的掺杂率的增加,各PSnT膜中的迁移率相继增大,n增大,迁移率在更低的掺杂率处开始增大,其增幅随着n的增加而增大.PS14T迁移率的增幅超过4个数量级,已与电化学合成的聚噻吩膜中观察到的迁移率增幅相当,表明此共聚物中的π-共轭长度已足以再现聚噻吩传导性能.

Mobilities of charge carriers in thin films of a series of copolymers with repeat units consisting of monosilanylene and oligothienylene （PSnT, n denotes the ring number of an oligothienylene unit） are measured over a wide range of doping levels. Mobilities of charge carriers in these polymer films coincide well with each other in the very low doping regions below a doping level of 0. 2%. The mobilities for these copolymer films increase as the doping level increases. Mobilities for the polymers with larger n start to rise at lower doping levels. The mobility enhancement follows an increasing order of the or-conjugation length. For PSI4T, the enhancement exceeds 104, close to that observed for electrochemically synthesized polythiophene, implying that the or-conjugation length in this polymer is almost sufficient to reproduce charge transport properties of polythiophenes.