聚合物光折变材料聚乙烯咔唑的陷阱态研究

Study on Trap States in Photorefractive Polymer of Polyvinylcarbazole

利用热激电流（TSC）技术测量了聚合物光折变材料聚乙烯咔唑（PVK）的退极化电流曲线，获得了热激弛豫过程的活化能。发现聚乙烯咔唑材料的热激退极化电流曲线共有两个峰，低温峰位于338K，对应的活化能约0．6eV，高温峰位于417K，对应的活化能范围在0．53～1．00eV，在0．77eV处呈现最大值，陷阱密度极大值为5．7×10^13cm^-2。同时证明了低温峰是源于偶极子退取向弛豫，高温峰则来自于陷阱中空穴的热释放。

The measurement of thermally stimulated current （TSC） spectrum was completed in photorefractive polymer of polyvinylcarbazole （PVK）. The active energy of the thermally stimulated relaxation process in PVK was obtained. The results show that there are two peaks in TSC spectrum of PVK, the low-temperature peak at 338 K has 0.6 eV active energy, while the high-temperature peak at 417 K has the active energy ranging from 0.53 to 1.00 eV, and the distribution was similar to Gauss law with a 0.77 eV maximum. The maximum of trap density is 5.7×10^13 cm^-3. Meanwhile, it is proved that the low-temperature originates from the reorientation relaxation of carbazole group and the high-temperature peak originates from the thermo-release of holes in the trap states.