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

有机半导体如并五苯具有小的介电常数和非常大的电子和空穴的有效质量。它使它们成为理想的候选人，以寻找新的电子相关现象，如最近的演示所示的分数量子霍尔效应和超导性的场效应晶体管的基础上并四苯和并三苯。1-3在这里，我们希望进行低温磁输运调查（如有必要也磁光和回旋共振研究，以确定有效质量）单晶场效应晶体管，满足以下挑战：低温p-和n-欧姆接触，无泄漏栅极隔离，良好的表面质量和最大的抑制非本征散射过程。具有这些先决条件的场效应晶体管开启了与分数量子霍尔效应、2D中的金属-绝缘体转变、维格纳结晶、自旋和电荷密度波以及超导性和磁有序之间的竞争相关现象的整个实验谱。尽管我们强调基本的、基础的电子输运机制，但上述关于接触、栅极隔离和表面形态的规格对于应用具有同等的相关性。

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.