ENVINTRADOT · Next generation environmentally friendly intraband active colloidal quantum dots and their ultrafast carrier dynamics for mid infrared photodetector

Infrared technology has found widespread applications across various fields, including remote controls, telecommunications networks, and thermal imaging etc. Traditional semiconductor alloys like indium gallium arsenide, mercury cadmium telluride and indium antimonide have been commonly employed as active materials in infrared devices. However, the manufacturing and assembly processes for these materials are highly complex and costly. To overcome these challenges and potentially replace expensive epitaxially fabricated devices, colloidal quantum dots (CQDs) have emerged as a promising alternative. In contemporary scientific exploration, there has been a surge of interest in narrow bandgap CQDs, thanks to their remarkable capacity to finely adjust excitonic transitions within the mid-wave infrared (mid-IR) spectrum. The discovery of intraband transition (1Se/h-1Pe/h) has opened as an alternative source of narrow energy transition occurs in the quantized conduction/valence band states of CQDs. Numerous research groups have extensively investigated the fundamental aspects and practical applications of HgE (where E = S, Se, and Te) CQDs.Leveraging numerous recent scientific breakthroughs in the domain of intraband (1Se-1Pe) active colloidal quantum dots, we will integrate state-of-the-art material processing techniques across chemistry, physics, and engineering. We will assess the dynamics of charge carriers through the utilization of femtosecond mid-IR transient absorption spectroscopy. In addition, we will focus on optimizing the required surface environment capable of maintaining intraband transitions under ambient conditions, at the same time offering adequate optoelectronic properties (mobility, conductivity) for their implementation in photodetector devices. Ultimately, our objective is to produce mid-IR photodetector devices incorporating the highly compatible non- toxic Ag2Se and core-shell CQDs.