6533b855fe1ef96bd12b1a8a

RESEARCH PRODUCT

Negative capacitance caused by electron injection through interfacial states in organic light-emitting diodes

ÁNgeles PitarchHenk J. BolinkGermà Garcia-belmonteJuan Bisquert

subject

Materials sciencebusiness.industryBand gapFermi levelGeneral Physics and Astronomylaw.inventionMetalsymbols.namesakeDipolelawvisual_artOLEDvisual_art.visual_art_mediumsymbolsOptoelectronicsPhysical and Theoretical ChemistrybusinessDiodeLight-emitting diodeNegative impedance converter

description

The negative capacitance frequently observed at low frequencies in organic light-emitting diodes (LEDs) is explained as a signature of sequential electron injection at the organic/metal interface first to states in the bandgap in the dipole layer and then to bulk states. The negative capacitance occurs when the interfacial states depart from equilibrium with the metal Fermi level due to an increasing rate of hopping to the bulk states. A simple kinetic model compares well with the experimental results and provides a new tool to investigate interfacial properties for improving the performance of organic LEDs.

yearjournalcountryeditionlanguage
2006-04-01Chemical Physics Letters
https://doi.org/10.1016/j.cplett.2006.02.060