Photonic Curing of Semiconductor Nanocrystals for High-Performance Flexible Electronics

摘要：非技术性描述：本研究的基本目标是在新兴的柔性电子领域取得革命性进展。手机和平板电脑的核心构件是计算机芯片，这些芯片易碎、刚性强、制造成本高。相比之下，正在探索新的材料和制造方法，使这些计算机芯片能够建立在薄，灵活的塑料片上。这些可以弯曲、滚动、折叠和随人体移动的柔性电子系统将使刚性芯片和电路根本不可能实现的工具成为可能。 柔性显示器、电子纺织品、生物传感器和可穿戴医疗设备只是将受益于轻质、低成本柔性电子设备的少数应用。在这项研究中，研究人员将探索如何用短暂的强光闪烁加热纳米尺寸的颗粒--小到足以在一根头发的宽度上首尾相连地容纳10，000个颗粒--以制造用于柔性电子产品的上级材料。技术描述：这项研究将探索新材料和制造方法，以实现高性能柔性电子产品。研究人员将合成铟镓锌氧化物（IGZO）的基于溶液的电子材料（“墨水”），然后通过将墨水直接沉积在塑料基板上来制造柔性晶体管。在沉积到衬底上之后，材料经历热处理以改善其电特性。更高的温度通常导致更高质量的材料，但柔性塑料基板通常不能被加热到约200 ℃以上。一种被称为光子固化的技术--使用闪光灯将薄膜瞬时加热到高温，而不足以加热基板造成损坏--将被用来帮助解决这一问题。本研究的主要目的是了解光固化对柔性基底上金属氧化物薄膜的形貌和电子性质的影响。这些知识将用于在柔性衬底上设计高性能晶体管。 这项拟议中的研究是明尼苏达大学首席研究员研究小组和NovaCentrix公司之间的一个合作项目，有效地将纳米材料合成、薄膜表征和晶体管设计方面的专业知识与光子固化领域的行业领导者结合在一起。研究人员将对材料和器件进行详细的表征，以实现对光子固化如何影响金属氧化物薄膜的形态，结晶度，成分和电子特性的基本物理理解。这项研究将阐明导致观察到的晶体管行为的物理机制，并确定限制薄膜晶体管性能的因素，以便减轻这些因素。对光子固化作为陶瓷薄膜传统热处理的替代方案的更深入的基本理解可能会在广泛的柔性电子系统中带来改变游戏规则的进步。

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.