Doping and photo-induced current in discotic liquid crystals thin films: Long-time and temperature effects

作者：Calo Annalisa; Stoliar Pablo; Cavallini Massimiliano^*; Geerts Yves H; Biscarini Fabio

来源：Organic Electronics, 2011, 12(5): 851-856.

DOI：10.1016/j.orgel.2011.02.007

• Discotic liquid crystals
• Photocurrent
• Time and temperature stability

Here we address the problem of time and temperature instability of the electrical current related to parasitic doping effects in discotic liquid crystals (DLCs). We investigated the electrical transport in thin films of a phthalocyanine-based DLC in-dark and upon laser irradiation during long thermal cycles. Measuring the electrical transport between two electrodes we observed that in-dark the current is mostly due to doping levels while, upon laser irradiation, the photocurrent reflects the diffusion length of the photogenerated charge carriers and it is limited by the coherence length of a column. We prove here that the two contributions are completely independent. Our result experimentally supports the theoretical studies performed at the molecular level on discotic liquid crystals.

• 出版日期2011-5