title: Enhanced Luminance of Electrochemical Cells with a Rationally Designed Ionic Iridium Complex and an Ionic Additive.
abstract: Light-emitting electrochemical cells (LEECs) offer the potential for high efficiency operation from an inexpensive device. However, long turn-on times and low luminance under steady-state operation are longstanding LEEC issues. Here, we present a single-layer LEEC with a custom-designed iridium(III) complex and a lithium salt additive for enhanced device performance. These devices display reduced response times, modest lifetimes, and peak luminances as high as 5500 cd/m(2), 80% higher than a comparable device from an unoptimized complex and 50% higher than the salt-free device. Improved device efficiency suggests that salt addition balances space charge effects at the interfaces. Extrapolation suggests favorable half-lives of 120 ± 10 h at 1000 cd/m(2) and 3800 ± 400 h at 100 cd/m(2). Overall, complex design and device engineering produce competitive LEECs from simple, single-layer architectures.
authors.affiliation: Department of Chemistry, The University of Texas at Austin , 105 E. 24th Street, Stop A5300, Austin, Texas 78712-1224, United States.
authors.forename: Kristin J
authors.initials: KJ
authors.lastname: Suhr
authors.affiliation: Department of Physics, The University of Texas at Dallas , 800 West Campbell Road, PHY 36, Richardson, Texas 75080-3021, United States.
authors.forename: Lyndon D
authors.initials: LD
authors.lastname: Bastatas
authors.affiliation: Department of Physics, The University of Texas at Dallas , 800 West Campbell Road, PHY 36, Richardson, Texas 75080-3021, United States.
authors.forename: Yulong
authors.initials: Y
authors.lastname: Shen
authors.affiliation: Department of Chemistry, The University of Texas at Austin , 105 E. 24th Street, Stop A5300, Austin, Texas 78712-1224, United States.
authors.forename: Lauren A
authors.initials: LA
authors.lastname: Mitchell
authors.affiliation: Department of Chemistry, The University of Texas at Austin , 105 E. 24th Street, Stop A5300, Austin, Texas 78712-1224, United States.
authors.forename: Bradley J
authors.initials: BJ
authors.lastname: Holliday
authors.affiliation: Department of Physics, The University of Texas at Dallas , 800 West Campbell Road, PHY 36, Richardson, Texas 75080-3021, United States.
authors.forename: Jason D
authors.initials: JD
authors.lastname: Slinker
keywords: ionic additives; ionic iridium complex; ionic transition metal complex; light-emitting electrochemical cells; luminance; organic light-emitting diodes