Absorption saturation in PbS-quantum dots

Summary form only given. PbS is an attractive semiconductor for the fabrication of quantum dots (QDs) because of its large bulk Bohr exciton radius (18 nm). The strong quantum confinement regime is thus easily obtained and the ground-state absorption edge can be tuned over a wide wavelength range (from the visible to the near infrared). Moreover, due to a smaller surface/volume ratio, surface states should play a minor role in PbS QDs compared to the II-VI semiconductor-doped glasses. These features are confirmed by our absorption saturation measurements in different PbS-doped glasses at room temperature.