Organic Field-Effect-Transistors for the Study of Correlation Phenomena

并五苯等有机半导体具有很小的介电常数和非常大的电子和空穴有效质量。它使它们成为寻找新的电子相关现象的理想候选者，正如最近在基于四烯和五烯的场效应晶体管中证明的分数量子霍尔效应和超导性。1-3在这里，我们希望对满足以下挑战的单晶场效应晶体管进行低温磁输运研究（如果必要的话，也进行磁光和旋转加速器共振研究以确定有效质量）：低温p欧姆和n欧姆接触，无泄漏栅极隔离，良好的表面质量和最大限度地抑制外部散射过程。具有这些先决条件的场效应晶体管开启了一系列与分数量子霍尔效应、二维金属-绝缘体跃迁、维格纳结晶、自旋和电荷密度波以及超导和磁有序之间的竞争相关现象的实验。尽管我们强调的是基本的、基本的电子输运机制，但上述关于触点、栅极隔离和表面形貌的规范与应用同样相关。

Organic semiconductors such as pentacene are endowed with a small dielectric constant and very large effective masses for both electrons and holes. It turns them into ideal candidates to search for novel electron correlation phenomena, as indicated by the recent demonstrations of the fractional quantum Hall effect and superconductivity in field effect transistors based on tetracene and penctacene. 1-3 Here we wish to perform low-temperature magneto-transport investigations (if necessary also magneto-optical and cyclotron resonance studies to determine the effective masses) on single crystal field effect transistors that meet the following challenges: low-temperature p- and n-ohmic contacts, leakage-free gate isolation, good surface quality and maximum suppresion of extrinsic scattering processes. Field effect transistors with these prerequisites open up an entire spectrum of experiments on correlation phenomena related to the fractional quantum Hall effect, the metal-insulator transition in 2D, Wigner crystallization, spin an charge density waves, and the competition between superconductivity and magnetic ordering. The above specifications on contacts, gate isolation and surface morphology are of equal relevance for applications, despite our emphasis on basic, fundamental electronic transport mechanimus.