Photonic Curing of Semiconductor Nanocrystals for High-Performance Flexible Electronics

University Of Minnesota-Twin Cities, Minneapolis MN

Investigators

Abstract

ABSTRACT: Non-technical description: The fundamental goal of this research is to make revolutionary advances in the emerging field of flexible electronics. The core building blocks of cell phones and tablet computers are computer chips that are fragile, rigid, and expensive to manufacture. In contrast, new materials and manufacturing methods are being explored that will enable these computer chips to be built on thin, flexible, plastic sheets. These flexible electronic systems that can bend, roll, fold, and move with the human body will enable tools that are simply not possible with rigid chips and circuits. Flexible displays, electronic textiles, biosensors, and wearable medical devices are just a few applications that will benefit from lightweight, low-cost, flexible electronic devices. In this research, the investigators will explore how nanometer-sized particles -small enough to fit 10,000 of them end to end across the width of a single human hair- can be heated with brief flashes of intense light to make superior materials for flexible electronics. Technical description: This research will explore novel materials and fabrication methods to enable high-performance flexible electronics. The investigators will synthesize solution-based electronic materials ("inks") of indium-gallium-zinc-oxide (IGZO), then fabricate flexible transistors by depositing the ink directly onto plastic substrates. After deposition onto the substrate, the materials undergo a heat treatment to improve their electrical characteristics. Higher temperatures generally result in higher quality materials, but the flexible plastic substrates typically cannot be heated above ~200C. A technique called photonic curing -using flash lamps to transiently heat the thin film to a high temperature without heating the substrate enough to cause damage- will be used to help address this tradeoff. The key research objective is to understand how the morphological and electronic properties of metal oxide nanocrystal thin films on flexible substrates are affected by photonic curing. That knowledge will be used to design high performance transistors on flexible substrates. The proposed research is a collaborative project between the principal investigator's research group at the University of Minnesota and NovaCentrix Corp., effectively bringing together expertise in nanomaterial synthesis, thin film characterization, and transistor design with the industry leader in photonic curing. The investigators will perform detailed characterizations of the materials and devices to achieve a fundamental physical understanding of how photonic curing affects the morphology, crystallinity, composition, and electronic characteristics of metal oxide nanocrystal thin films. This research will elucidate the physical mechanisms that lead to observed transistor behavior and identify the factors that limit thin-film transistor performance so they can be mitigated. A deeper fundamental understanding of photonic curing as an alternative to traditional thermal treatments of ceramic thin films could result in game-changing advances in a wide array of flexible electronic systems.