Photocarrier Generation in Smectic Phenylnaphthalene Liquid Crystalline Photoconductor
Photocarrier Generation in Smectic Phenylnaphthalene Liquid Crystalline Photoconductor
复制标题
近晶苯基萘液晶光电导体中光载流子的产生
DOI：
10.1021/jp9910082
复制
发表时间：
1999
影响因子：
3.3
通讯作者：
J. Hanna
中科院分区：
文献类型：
--
作者：
Hong Zhang;J. Hanna
利用飞行时间瞬态光电流技术研究了近晶液晶光导体2-（4′-辛基苯基）-6-十二烷基萘（8-PNP-O12）不同相的本征空穴光产生过程和光强的函数关系。发现所收集的光电电荷与光强的平方成正比，与相无关。假设双激子相互作用过程中的Onsager型载流子生成模型与实验结果吻合较好。发现分子的排序促进了电子-空穴对的解离。热化距离r0非常大，与蒽等分子晶体的热化距离相当，说明近晶中间相的载流子生成过程类似于有机分子晶体，而不是有机液体。
The intrinsic hole photogeneration process in different phases of a smectic liquid crystalline photoconductor, 2-(4‘-octylphenyl)-6-dodecyloxynaphthalene (8-PNP-O12) was investigated as a function of electric field and light intensity by using the time-of-flight transient photocurrent technique. The collected photogeneration charges were found to be approximately proportional to the square of the light intensity irrespective of the phases. A model assuming Onsager type of carrier generation involving double-exciton interaction process, gave a good agreement with the obtained experimental results. The molecular ordering is found to promote the dissociation of the electron−hole pairs. The thermalization distance, r0, was very large and comparable with those in molecular crystals such as anthracene, indicating that the carrier generation process in smectic mesophases is analogous to that in organic molecular crystals rather than that in organic liquids.