Photonic Curing of Semiconductor Nanocrystals for High-Performance Flexible Electronics

摘要：非技术描述：这项研究的根本目标是在新兴的柔性电子领域取得革命性的进展。手机和平板电脑的核心组成部分是脆弱、僵硬、制造成本高昂的计算机芯片。相比之下，人们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的、灵活的塑料板上。这些灵活的电子系统可以与人体一起弯曲、滚动、折叠和移动，这将使工具成为刚性芯片和电路无法实现的工具。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几个将受益于轻便、低成本、灵活的电子设备的应用。在这项研究中，研究人员将探索如何通过短暂的强光闪光来加热纳米尺寸的颗粒--小到可以在一根头发的宽度上首尾相连地容纳1万个纳米颗粒--以制造出用于柔性电子产品的优质材料。技术描述：这项研究将探索新的材料和制造方法，以实现高性能的柔性电子产品。研究人员将合成基于溶液的铟-镓-锌氧化物(IGZO)电子材料(墨水)，然后通过将墨水直接沉积到塑料基板上来制造柔性晶体管。在沉积到衬底上后，材料经过热处理以改善其电学特性。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无法加热到约200摄氏度以上。一种名为光子固化的技术-使用闪光灯将薄膜瞬时加热到高温，而不会对衬底进行足够的加热以造成损害-将有助于解决这一权衡问题。主要的研究目标是了解柔性衬底上的金属氧化物纳米晶薄膜的形态和电学性质是如何受到光子固化的影响的。这些知识将被用于在柔性衬底上设计高性能晶体管。这项拟议的研究是明尼苏达大学首席研究员研究小组与NovaCentrix公司的合作项目，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先者结合在一起。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纳米晶薄膜的形态、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，以便缓解这些因素。对光子固化作为陶瓷薄膜传统热处理的替代方案的更深层次的基本理解，可能会在一系列灵活的电子系统中带来改变游戏规则的进展。

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.