Zernike Institute for Advanced Materials, University of Groningen , Nijenborgh 4, 9747AG Groningen, Netherlands.
Department of Chemistry and Applied Biosciences, ETH Zürich , Vladimir Prelog Weg 1, Zürich 8093, Switzerland.
ACS Appl Mater Interfaces. 2018 Feb 14;10(6):5626-5632. doi: 10.1021/acsami.7b16882. Epub 2018 Feb 2.
Colloidal quantum dots are a class of solution-processed semiconductors with good prospects for photovoltaic and optoelectronic applications. Removal of the surfactant, so-called ligand exchange, is a crucial step in making the solid films conductive, but performing it in solid state introduces surface defects and cracks in the films. Hence, the formation of thick, device-grade films have only been possible through layer-by-layer processing, limiting the technological interest for quantum dot solids. Solution-phase ligand exchange before the deposition allows for the direct deposition of thick, homogeneous films suitable for device applications. In this work, fabrication of field-effect transistors in a single step is reported using blade-coating, an upscalable, industrially relevant technique. Most importantly, a postdeposition washing step results in device properties comparable to the best layer-by-layer processed devices, opening the way for large-scale fabrication and further interest from the research community.
胶体量子点是一类溶液处理型半导体，在光伏和光电应用方面具有广阔的前景。去除表面活性剂（即配体交换）是使固体薄膜具有导电性的关键步骤，但在固态下进行配体交换会在薄膜中引入表面缺陷和裂纹。因此，只有通过层层处理才能形成厚的、器件级的薄膜，这限制了量子点固体的技术应用。在沉积之前进行溶液相配体交换，可以直接沉积适合器件应用的厚而均匀的薄膜。在这项工作中，采用刮刀涂布法（一种可扩展的、具有工业相关性的技术）在单个步骤中报告了场效应晶体管的制造。最重要的是，后沉积清洗步骤使得器件性能可与最佳的层层处理器件相媲美，为大规模制造和研究界的进一步关注开辟了道路。
