S. Becker, E. Salikhova, J.S. Niehaus
Fraunhofer CAN,
Germany
Keywords: NIR, quantum dots, sensors, security application, continuous flow
Summary:
Near infrared (NIR) quantum dots have been the subject of intensive research in variety of different fields of application, e.g., absorber materials in solar cells. In the last years, the request of sensors for the NIR wavelength range increased dramatically due to new applications like augmented reality or Smart Farming. The integration of such sensor into smart device require a high degree of miniaturization. For these reasons, NIR quantum dots are of greater interest than ever before. In this work, we will present the synthesis of such NIR quantum dots, including a continuous flow based approach for the reproducible mass production of these quantum dots. These NIR quantum dots cover the spectral range from 800 to 2000 nm. Unfortunately, the as-synthesized particles are usually not suitable for the direct use in applications, due to stability reasons or incompatibilities with the further processing. Therefore, we will address the (post-)synthesis modification of the quantum dots to meet the requirements of different applications. Beside the conventional PbS NIR quantum dots we will focus on Pb-free InAs based quantum dots as a heavy metal free alternative. We will discuss the various challenges involved in their synthesis. A direct comparison of the two particles systems should not only show the respective strengths and weaknesses, but also to provide an outlook for future development. Finally, we will show some examples how our NIR quantum dots are used in different project and applications.