Lead and lead-free quantum dot inks simplify solution processing for SWIR photodetectors

Photodetection in the short-wave infrared (SWIR) is preparing to transform from a niche market with high-cost products to mass market adoption of disruptive technologies. Quantum Dot (QD) absorbers have several unique advantages including spectral range, cost effective production, and potential for high resolution. To process QD absorber layers the current approach deposits up to 10 layers with ligand exchange performed on each layer, complicating processing, and increasing the probability for defect formation. An ideal approach would utilise a QD ink that enables the QD absorber layer to be deposited in a single step. Lead free quantum dot materials are an attractive prospect particularly for applications in the consumer market where environmental and health concerns are strongly associated with branding. A lack of lead free QD materials with absorption in the SWIR or quality matching those of the Pb counterparts has kept Pb QDs as the most widely used material to date. Quantum Science Ltd. presents progress in both areas.