We herein present the results of a study on the novel fabrication process of uniform and homogeneous semiconducting polymer layers, in this case hole-injecting and fluorescent light-emitting layers that were produced by a simple solution-coating process for 3D conformal organic light-emitting diodes (3D OLEDs) on curvilinear surfaces. The solution-coating process used was a newly developed method of vortex-flow-assisted solution-coating with the support of spinning of the coating solution. It is shown that the vortex-flow-assisted spin-coating process can produce high-quality thin films at nanoscale thicknesses by controlling the liquid surface of the coating solutions, which can easily be adjusted by changing the spinning speed, even on complex curvilinear surfaces, i.
View Article and Find Full Text PDFSpin-coated self-assemblies of colloidal particles have been developed recently as an attractive close-packed monolayer of the particles for a variety of applications, but they are limited by the small area of their monolayers, especially given their low uniformity and monolayer coverage on large-area substrates. We report several noteworthy characteristics of a close-packed monolayer of polystyrene nanospheres (PS NSs) fabricated using a simple and inexpensive spin-coating method with a PS NS suspension mixed using the nonionic surfactant polyoxyethylene (12) tridecyl ether (PEO-TDE). In our study, we show that the PEO-TDE surfactant offers excellent wettability, surface tension, and a slow solvent evaporation rate of the PS NS suspension, similar to the conventional surfactant Triton X-100.
View Article and Find Full Text PDFPolymeric light-emitting materials have been developed recently as an attractive solution-processable alternative to conventional vacuum-deposited small molecules in organic/polymeric light-emitting diodes, but they are still limited in terms of their performance, especially with low luminance and efficiency. We report on some noteworthy characteristics of a new type of single emitting layer (EML), composed of a blend of a host blue-emitting polyspirobifluorene-based copolymer and a guest yellow-emitting poly(p-phenylene vinylene) derivative copolymer. These host and guest polymers have nearly identical highest occupied molecular orbital levels of about 5.
View Article and Find Full Text PDFSurface-emitting organic light-emitting transistors (OLETs) could well be a core element in the next generation of active-matrix (AM) displays. We report some of the key characteristics of graphene-based vertical-type organic light-emitting transistors (Gr-VOLETs) composed of a single-layer graphene source and an emissive channel layer. It is shown that FeCl doping of the graphene source results in a significant improvement in the device performance of Gr-VOLETs.
View Article and Find Full Text PDF