Novel INFIQ® Lead-Free Infrared Quantum Dot Inks for Photodetection Applications

红外(IR)光检测在许多行业中使用，在这些行业中，传感和成像的独特特性增加了可见光以外的重要功能。目前的市场包括电信、监控、光谱、热成像和医疗保健，对消费/移动设备、自动驾驶汽车和新型医疗诊断的应用需求不断增长。基于胶体量子点(CQD)的红外光电探测器显示出非凡的前景，可以颠覆结合波长可调、高响应度和溶液可加工性的现有红外技术。目前占主导地位的技术使用硫化铅(PbS)纳米颗粒。铅(铅)是RoHS指令2011/65/EU中限制的危险物质；它是一种重金属，对环境和健康有影响。一种最佳的方法将避免这种合规问题，同时将产品从制造到最终处置的生命周期中对健康和环境的影响降至最低。PBS QD设备还需要涉及多达14层的逐层沉积过程。每一层都需要多次化学处理和清洗步骤，使用大量昂贵且必须安全处置的化学品和溶剂。本项目将通过开发新型无铅量子点墨水来解决所有这些问题，并通过简单的一步沉积过程展示其在短波红外(SWIR)光电探测器中的应用。到目前为止，替代的无铅量子点材料还没有被合成出足够高的质量和足够大的规模用于光电子器件。量子科学有限公司(QS)拥有制造可扩展的无铅SWIR CQD的专利工艺和技术诀窍，展示了用于光检测的红外光的高效转换。目前的挑战是实现材料合成的规模化，并提供处于合适状态的量子点，以实现简单且低成本的CQD薄膜涂层，用于大规模生产SWIR光电探测器。在本项目中，将采用扩大规模的方法合成无铅CQD，并在同一合成反应器中使用导电配体对表面进行功能化，而不需要对合成的QD进行预纯化。该项目将评估不同的预先筛选的新型配体、环保溶剂和工艺条件，并将优化QD油墨配方并将其用于沉积薄膜用于器件制造。该项目将提供在器件中具有领先性能的无铅CQD油墨，用于大规模生产高性能SWIR光电二极管，以满足客户下一阶段商业化的要求。

Photodetection of infrared (IR) light is used in many industries where the unique properties of sensing and imaging add significant capabilities beyond those of visible light. Current markets include telecommunications, surveillance, spectroscopy, thermal imaging and healthcare, with growing demand in applications for consumer/mobile devices, autonomous vehicles, and novel medical diagnostics.Colloidal quantum dot (CQD)-based IR photodetectors have shown exceptional promise to disrupt incumbent IR technologies combining wavelength tunability, high responsivity and solution processability. The current dominant technology uses lead sulphide (PbS) nanoparticles. Lead (Pb) is restricted hazardous substances under RoHS Directive 2011/65/EU; it is a heavy metal and carries environmental and health concerns. An optimal approach would avoid such compliance issue whilst minimising health and environmental impacts in a product's life cycle, from manufacture to eventual disposal.The PbS QD devices also require a layer-by-layer deposition process involving up to 14 layers. Each layer requires multiple chemical treatment and washing steps, using large volumes of chemicals and solvents that are costly and must be disposed of safely.This project will solve all these problems by developing novel lead-free QD inks and demonstrate their applications in short-wave infrared (SWIR) photodetectors, through a simple one step deposition process. To date, alternative lead-free QD materials have not been synthesised with sufficiently high quality and large scale for optoelectronic device applications. Quantum Science Ltd (QS) has proprietary processes and know-hows to make scalable lead-free SWIR CQDs demonstrating highly efficient conversion of IR light for photodetection. The current challenge is to upscale the material synthesis and provide the QDs in right status enabling simple and low-cost CQD film coating for mass production of SWIR photodetectors.In this project the lead-free CQDs will be synthesised using upscaling method, and surface functionalised with conductive ligands in the same synthesis reactor without pre-purification of the synthesised QD. Different pre-screened novel ligands, eco-friendly solvents and processing conditions will be assessed and QD ink formulations will be optimised and used to deposit films for device fabrication.This project will deliver lead-free CQD inks with leading performance in devices for mass production of high-performance SWIR photodiodes to meet our customers' requirements for the next stage of commercialisation.