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Area emission is realized in all-solution-processed hybrid light-emitting transistors (HLETs). A new HLET design is presented with increased aperture ratio, and optical and electrical characteristics are shown.

Abstract Area emission is realized in all-solution-processed hybrid light-emitting transistors (HLETs). A new HLET design is presented with increased aperture ratio, and optical and electrical characteristics are shown.

Two new heteroleptic Pt(II) complexes bearing an n-hexyloxy substituted phenyllepidine-based ligand and either a picolinate (pic) or acetylacetonate (acac) coligand are synthesized for use in organic light-emitting field-effect transistors (LEFETs). Both compounds are obtained in good yields via a short and straightforward synthetic route. It is found that while both Pt(II) complexes show good chemical stability and solubility, the coligand affects the photoluminescence quantum yield and crystal packing of the complexes. Although aggregate induced phosphorescence enhancement is not observed, it is found that high concentrations of the emitters in a poly[bis(4-phenyl) (2,4,6-trimethylphenyl) amine] host lead to improved charge injection in hybrid LEFETs. LEFETs with area emission, high ON/OFF ratios (> 10(6)) and mobilities (approximate to 1.3 cm(2) V-1 s(-1)), and external quantum efficiencies of up to 0.1% at the highest brightness of 855 cd m(-2) are demonstrated.

Abstract M. Ullah, E. B. Namdas, and co-workers present on page 6410 the first all-solution-processed hybrid light-emitting transistors, and demonstrate the effectiveness of their operation with three organic emissive materials. This approach involves the fabrication of a bilayer device structure using a solution of organic emissive material, and a sol–gel of zinc tin oxide. The use of nonplanar contacts is also demonstrated in this study as playing a crucial role in the enhanced optoelectronics characteristics.

Organic light emitting field effect transistors (LEFETs) integrate light emission of a diode with logic functions of a transistor into a single device architecture. This integration has the potential to provide simplified displays at low costs and access to injection lasing. However, the charge carrier mobility in LEFETs is a limiting factor in realizing high current densities along with a trade-off between brightness and efficiency. Herein, we present a technique controlling the nanoscale morphology of semi-conducting polymers using nanoscale grooved substrates and dip-coating deposition to achieve high current density. We then applied this approach to heterostructure LEFETs and demonstrated brightness exceeding 29000 cd m(-2) at an EQE of 0.4% for a yellow emitter and 9600 cd m(-2) at an EQE of 0.7% for a blue emitter. These results represent a significant advancement in organic optoelectronics and are an important milestone toward the realization of new applications in displays and electrically pumped lasing.