Anomalous photovoltaic effect based on spontaneous polarization of ferroelectric liquid crystals

合成了含有十烯基、二硅氧烷链和四环硅氧烷环的铁电液晶苯基四硫吩衍生物。这些化合物表现出手性近晶C(SMC*)相，其自发极化超过100nCCM-2。用飞行时间法测定的空穴迁移率约为1×10~(-4)cm~2V~(-1)s~(-1)。含癸烯基团的化合物在SMC*相表现出反常的光伏效应。应该注意的是，即使是含有大体积环四硅氧烷环的化合物也表现出一种各向同性的SMC*相。该化合物在SMC*相中表现出反常的光伏效应。在ZER偏置下，当样品在光照前施加直流偏置时，会产生反向光电流。在光照前，零偏置光电流的极性随直流偏置的符号变化。

Ferroelectric liquid-crystalline (LC) phenylterthiophene derivatives bearing a decenyl group, a disiloxane chain, and a tetracyclosiloxane ring has been synthesized. These compounds exhibit a chiral smectic C (SmC*) phase, where its spontaneous polarization exceeds 100 nCcm-2. The hole mobilities determined by a time-of-flight method were on the order of 1x10-4 cm2V-1s-1. The compound having decenyl group exhibits an anomalous photovoltaic effect in the SmC* phase. It should be noted that even the compound bearing a bulky cyclotetrasiloxane ring exhibit an enatiotropic SmC* phase. The compound bearing a decenyl chain exhibits anomalous photovoltaic effect in the SmC* phase. Under zer-bias, photocurrent in the reversed direction was generated when DC bias was aplied to the sample before light illumination. The polarity of the zero-bias photocurrent was changed by the sign of the DC bias before the illumination.