Electric field-driven charge transport in crystalline rubrene

• 作 者: FengXu;ZhigangShuai;
• 机 构: Department of Chemistry,Tsinghua University,100084 Beijing,China
• 出 处: 第十二届全国量子化学会议
• 发表日期: 2014年期

　　In this study we calculate the charge transport properties in crystalline rubrene under electric field.By taking nuclear tunneling effect into account,charge transfer rates evaluated from Fermi golden rule1 is shown to be band-like for downward hopping with energy offsets smaller than 50meV,and temperature-activated for upward hopping.At low temperatures,an optimum transfer rate is obtained along the field direction where the energy offset is around 25meV.This optimum energy offset is significantly smaller than the one predicted by Marcus rate(150meV),demonstrating that nuclear vibrational effect dominates the field-driven motion.Our results explain the experimental observation of temperature-activated charge mobility when deep traps are introduced into crystalline rubrene after X-ray exposure2.