Colloidal synthesis

Colloidal synthesis forms the backbone of our research. In addition to enabling deeper physical insight in spectroscopic and transport studies and producing superior devices, synthetic advances such as shape control, charge (doping) control, passivation of undercoordinated surface atoms etc. are themselves important for the wider field of colloidal inorganic chemistry. Past synthesis-related milestones from the group include the introduction core/shell nanocrystal heterostructures, first chemical reduction (n-doping) of nanocrystals, elucidation of gold nanoparticle growth mechanisms, synthesis of superconducting metal nanoparticles, and the introduction of size-tunable HgTe nanoparticles for infrared optoelectronics.

The group currently focuses on the mercury chalcogenide (HgX, X = S, Se, Te) family of nanocrystals with infrared energy gaps in the 0.1 – 0.6 eV (2000 – 10000 nm wavelength) range. Synthetic efforts focus on improving the nanoparticle size distributions,  growing novel HgX/MX (M = metal) heterostructures and controlling the doping. The doping control and associated surface chemistry present especially rich challenges in HgX systems due to their small energy gaps. This allows chemical perturbations which are usually inconsequential to produce sizable effects, rendering HgX a unique platform for the study of nanoparticle interfacial chemistry.

Selected publications