Nonvolatile memory organic field effect transistor induced by the steric hindrance effects of organic molecules
作者:Mi-Hee Jung、Kyu Ho Song、Kyoung Chul Ko、Jin Yong Lee、Hyoyoung Lee
DOI:10.1039/c0jm00854k
日期:——
We report a nonvolatile memory organic field effect transistor (OFET) using ambipolar organic molecules as nano-interfaced semiconductor materials. Newly synthesized push-pull organic molecules (PPOMs) containing triarylamine as an electron donating group, thiophene as a spacer, and malononitrile as an electron withdrawing group are proposed. The tilted PPOMs with side chains could control the charge trapping of the conducting channel formed between pentacene and PPOMs. Quantum chemical calculations were carried out to estimate the dihedral angle at the neutral and electron charged anion molecules and to explain the charging effects for the memory OFET performance (write-read-erase-read cycles). The charge mobilities of OFETs comprising the nano-interfaced PPOMs were affected by the dihedral angles derived from the steric hindrance of the bulky side chain of the spacer. The memory OTFT with higher dihedral angle material exhibited a wider memory window as well as reduced current flow. The memory OFET devices showed a memory window of −40 to +40 V, a memory ratio of 100 for “ON” to “OFF” currents, and long retention time for the nonvolatile memory.
我们报告了一种非易失性记忆有机场效应晶体管(OFET),使用双极有机分子作为纳米接口半导体材料。提出了一种新合成的推拉型有机分子(PPOMs),其包含三芳胺作为电子供体,噻吩作为间隔层,和马隆腈作为电子吸引基团。倾斜的PPOMs带侧链,可以控制在戊烯与PPOMs之间形成的导电通道的电荷捕获。我们进行了量子化学计算,以估算中性和带负电荷的阴离子分子的二面角,并解释记忆OFET性能(写入-读取-擦除-读取周期)的充电效应。包含纳米接口PPOMs的OFET的电荷迁移率受限于来自于间隔层庞大侧链的立体阻碍所产生的二面角影响。使用更高二面角的材料的记忆OTFT展现出更宽的记忆窗口以及降低的电流流动。记忆OFET设备显示记忆窗口为−40到+40 V,"开启"到"关闭"电流的记忆比为100,并且具有较长的非易失性记忆保持时间。