HgTe QDs synthesis: (Caution: highly toxic materials and heavy metals are used and appropriate precautions have to be implemented.) The HgTe QDs were synthesized following a protocol by Shen et al. Briefly, 27.15 mg (0.1 mmol) HgCl2 were dissolved in 4 mL dried oleylamine at 100 °C for 1 hour under inert atmosphere. A mixture of 14.5 µL (0.05 mmol) of bis(trimethylsilyl)telluride in 0.5 mL anhydrous hexane was injected into the Hg 2+ containing solution. After 1 minute of QDs growth at 100 °C, the dispersion was quenched in 4 mL tetrachloroethylene. The QDs were precipitated from the dispersion by adding 3.6 mL methanol, centrifuged at 12100 rpm for 1 minute and the precipitate was dispersed in 0.9 mL tetrachloroethylene. The HgTe QDs were precipitated a second time with 0.5 mL methanol and centrifuged 12100 rpm for 1 minute. A small amount of the precipitate was dispersed in tetrachloroethylene, filtered through a 0.2 µm polytetrafluoroethylene syringe filter. The dispersion in tetrachloroethylene has been used to fabricate HgTe QDs thin films and measure their absorbance with Fourier-transform infrared spectroscopy. The main precipitate was dispersed in 0.5 mL dried tetradecane and filtered through a 0.2 µm polytetrafluoroethylene syringe filter. The QDs dispersion was stored under dry and inert atmosphere.