Tuning the metal/organic interface in a C60-based magnetic tunnel transistor

A. BEDOYA-PINTO; M. GOBBI; F. GOLMAR; R. LLOPIS; X. SUN; F. CASANOVA; L. HUESO

London

Encuentro; 4th International Meeting on Spins in Organic Semiconductors.; 2012

Organic semiconductors (OS) have emerged as a promising material class for spintronic applications, mainly due to their weak spin relaxation mechanisms which result in long spin lifetimes [1]. While recent efforts have focused on the spin injection and transport in organic semiconductors, less attention has been paid to the intrinsic properties of the molecular material. In this work, building on the fact that some OSs could behave as ordinary band-like semiconductors, we report the achievement of a magnetic tunnel transistor (MTT) which employs C60 as a semiconducting collector. We show that this device performs as a state-of-the-art MTT, with magnetocurrent values reaching 90% at room temperature. Furthermore, in order to exploit the chemical flexibility of organic materials, molecules with different electronic properties (CuPc, Alq3, F16CuPc) are used to modify the metal / C60 interface and study their effect on the device performance. At the same time, this C60-based magnetic tunnel transistor serves as a characterization tool to study the energy-level alignment of the interfacial molecule monolayers and to gain insights about the formation of hybrid states which might favour both change and spin injection across the metal/organic interface. [1] V.A. Dediu, L.E. Hueso, I. Bergenti, C. Taliani, Nature Mater. 2009, 8, 707