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

红外（IR）光的光探测被用于许多行业，在这些行业中，其独特的传感和成像特性增加了比可见光更重要的能力。目前的市场包括电信、监控、光谱、热成像和医疗保健，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。胶体量子点（CQD）红外光电探测器结合波长可调性、高响应性和溶液可加工性，显示出颠覆现有红外技术的非凡前景。目前的主流技术是使用硫化铅纳米颗粒。根据RoHS指令2011/65/EU，铅（Pb）是受限有害物质；它是一种重金属，会带来环境和健康问题。最佳方法将避免此类合规问题，同时在产品的生命周期（从制造到最终处置）中最大限度地减少对健康和环境的影响。PbS量子点器件还需要一个多达14层的逐层沉积过程。每一层都需要多次化学处理和洗涤步骤，使用大量昂贵的化学品和溶剂，必须安全处理。该项目将通过开发新型无铅量子点油墨来解决所有这些问题，并通过简单的一步沉积工艺展示其在短波红外（SWIR）光电探测器中的应用。迄今为止，替代无铅量子点材料还没有合成出足够高质量和大规模的光电子器件应用。量子科学有限公司（QS）拥有专有工艺和专有技术，可生产可扩展的无铅SWIR cqd，展示了用于光检测的高效红外光转换。目前的挑战是提高材料的合成水平，并提供适当状态的量子点，使简单和低成本的CQD薄膜涂层能够批量生产SWIR光电探测器。在本项目中，无铅cqd将采用升级法合成，并在同一合成反应器中使用导电配体进行表面功能化，而无需对合成的QD进行预纯化。不同的预筛选新型配体、环保溶剂和加工条件将被评估，QD油墨配方将被优化并用于沉积用于设备制造的薄膜。该项目将提供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.