论文部分内容阅读
本文研究了退火对C60膜电导率的影响.结果表明,从室温到200℃的温度范围内,C60膜具有明显的半导体性质,室温电导率在10-5~10-7(Ω·cm)-1的范围内.薄膜在200℃温度下恒温保持过程中,当时间小于2.5小时时电导率的增大是由于薄膜中不稳定的hcp相的减少引起的;而相互通连的晶粒数目的减少导致退火时间大于2.5小时的薄膜电导率的减小.相互通连的晶粒数目的减少使得晶间势垒变高,从而使电导率变小.通连晶粒间缺陷的减少导致激活能变大,这些缺陷在C60膜的能带中引入缺陷态.σ-1/T图中高温区域电导偏离直线是由于在退火过程中不稳定的结构相向稳定的fCC相转变.
This article studies the effect of annealing on the conductivity of C60 membranes. The results show that the C60 film has obvious semiconducting properties in the temperature range from room temperature to 200 ℃ and the room temperature conductivity is in the range of 10-5 ~ 10-7 (Ω · cm) -1. The increase in conductivity when the film is held at a constant temperature of 200 ° C for less than 2.5 hours is due to the reduction of the unstable hcp phase in the film; and the decrease in the number of interconnected grains leads to annealing A reduction of the conductivity of the film for more than 2.5 hours. The decrease in the number of interconnected grains causes the intergranular barrier to increase, thereby decreasing the electrical conductivity. The decrease of the intergranular defects leads to the increase of activation energy, and these defects introduce defect states into the C60 film’s energy band. The deviation from the straight line in the high-temperature region of the σ-1 / T diagram is due to the phase-stable fCC transformation of the unstable structure during the annealing process.