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Enhancing Light Emission in Interface Engineered Spin‐OLEDs through Spin‐Polarized Injection at High Voltages
Author(s) -
PrietoRuiz Juan Pablo,
Miralles Sara Gómez,
PrimaGarcía Helena,
LópezMuñoz Angel,
Riminucci Alberto,
Graziosi Patrizio,
Aeschlimann Martin,
Cinchetti Mirko,
Dediu Valentin Alek,
Coronado Eugenio
Publication year - 2019
Publication title -
advanced materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.707
H-Index - 527
eISSN - 1521-4095
pISSN - 0935-9648
DOI - 10.1002/adma.201806817
Subject(s) - materials science , oled , electroluminescence , optoelectronics , spintronics , ferromagnetism , spin (aerodynamics) , voltage , nanotechnology , condensed matter physics , layer (electronics) , electrical engineering , physics , engineering , thermodynamics
The quest for a spin‐polarized organic light‐emitting diode (spin‐OLED) is a common goal in the emerging fields of molecular electronics and spintronics. In this device, two ferromagnetic (FM) electrodes are used to enhance the electroluminescence intensity of the OLED through a magnetic control of the spin polarization of the injected carriers. The major difficulty is that the driving voltage of an OLED device exceeds a few volts, while spin injection in organic materials is only efficient at low voltages. The fabrication of a spin‐OLED that uses a conjugated polymer as bipolar spin collector layer and ferromagnetic electrodes is reported here. Through a careful engineering of the organic/inorganic interfaces, it is succeeded in obtaining a light‐emitting device showing spin‐valve effects at high voltages (up to 14 V). This allows the detection of a magneto‐electroluminescence (MEL) enhancement on the order of a 2.4% at 9 V for the antiparallel (AP) configuration of the magnetic electrodes. This observation provides evidence for the long‐standing fundamental issue of injecting spins from magnetic electrodes into the frontier levels of a molecular semiconductor. The finding opens the way for the design of multifunctional devices coupling the light and the spin degrees of freedom.