Large quantities of microscopic red, green, and blue light-emitting diodes (LEDs) made of crystalline inorganic semiconductor materials micro-transfer printed in large quantities onto rigid or flexible substrates form monochrome and color displays having a wide range of sizes and interesting properties. Transfer-printed micro-LED displays promise excellent environmental robustness, brightness, spatial resolution, and efficiency. Passive-matrix and active-matrix inorganic LED displays were constructed, operated, and their attributes measured. Tests demonstrate that inorganic micro-LED displays have outstanding color, viewing angle, and transparency. Yield improvement techniques include redundancy, physical repair, and electronic correction. Micro-transfer printing enables revolutionary manufacturing strategies in which microscale LEDs are first assembled into miniaturized micro-system "light engines," and then micro-transfer printed and interconnected directly to metallized large-format panels. This paper reviews micro-transfer printing technology for micro-LED displays. FIGURE 3 -(A) Schematic illustration of a micro-transfer stamp that is rigid in horizontal directions and compliant in the vertical dimension. (B) Photograph of a stamp on a 225 × 225 mm glass back. (C) SEM of the stamp posts.FIGURE 4 -Photograph of a 50 × 50 mm stamp silicon master (A) and elastomer stamp (B). The stamp has an array of 250 by 250 posts on a 200-micron pitch with 62,500 posts. Journal of the SID 25/10, 2017 591 FIGURE 9 -Micrographs of an array of microscopic inorganic light-emitting diodes microtransfer printed to a metal-coated substrate (left) and emitting red light (right). The anodes are connected in common with a transparent aluminum zinc oxide anode.
One important technical hurdle that has to be overcome for using organic transistors in radio-frequency identification tags is for these devices to operate at rf frequencies (typically 13.56MHz) in the front end. It was long thought that organic transistors are too slow for this. In this letter we show that organic transistor based full-wave rectifier circuits utilizing pentacene, a p-channel organic semiconductor, can operate at this frequency with a useful efficiency. In order to achieve such high-frequency operation, we make use of the nonquasistatic state of the transistors.
The present study introduces the silica-anchored azo-initiator 4,4′-azobis(4-cyano-N-(3″-triethoxysilylpropyl)-valeric amide) (ACTA) for the surface-initiated polymerization of methyl acrylate (MA) with and without additional grafted reversible addition–fragmentation chain transfer (RAFT) agents 1,4-bis(3′-trimethoxysilylpropyltrithiocarbonylmethyl)benzene and 1,6-bis(o,p-2′-trimethoxysilylethylbenzyltrithiocarbonyl)hexane. While the sole use of silica-linked ACTA produced grafted poly(methyl acrylate) (pMA) of high molecular weight, due to a 2D Trommsdorff effect, the polymerization in combination with the fixed RAFT agents exhibited living behaviour with increasing molecular weights during polymerization. Silica-pMA hybrids were further analyzed via thermogravimetric analysis and scanning electron microscopy, which revealed significant differences between the three approaches.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.