Abstract: Methods of fabricating nanocrystals are disclosed. Such methods may include providing copper sulfide core nanocrystals and providing a lead precursor. Moreover, the copper sulfide core nanocrystals may be reacted with the lead precursor to generate copper doped lead sulfide nanocrystals. Related nanocrystals and optoelectronic devices are also disclosed.

Abstract: A process for synthesizing Cu2-xS/PbS core/shell nanocrystals. Pb-oleate is mixed with 1-octadecene and heated to 60° C. Cu2-xS core solution and bis(trimethylsilyl)sulfide stock solution are added and the mixture is stirred at 60° C. for 6 minutes to form the PbS shell around the Cu2-xS nanocrystal cores. The flask is cooled and acetonitrile and toluene is added and the mixture is centrifuged to precipitate and remove the Cu2-xS/PbS core/shell nanocrystals from the reaction mixture. The reaction also produces homogeneously nucleated PbS nanocrystals, which are removed from the Cu2-xS/PbS core/shell reaction mixture via size-selective precipitation. By tailoring the amounts of Pb-oleate and bis(trimethylsilyl)sulfide stock solution in the reaction vessel, while maintaining their molar ratio of 1.5:1 and the number of Cu2-xS cores in the reaction, Cu2-xS/PbS core/shell nanocrystals having a predetermined shell thickness of PbS, and thus a predetermined level of chemical stability, can be obtained.

Abstract: Photodiodes configured to convert incident photons in the short-wave infrared (SWIR) to electric current, where the photodiodes have a PbS/PbClx core/shell nanocrystal absorber layer. The PbClx shell in the PbS/PbClx nanocrystals provide native passivation in the (100) crystal facets and enable removal of pre-device processing ligands and ligand exchange on the (111) crystal facets of the PbS/PbClx nanocrystals such that the photodiode exhibits reduced current densities under reverse bias and greater infrared photoresponse, providing improved device performance as compared to photodiodes having absorber layers formed from PbS core nanocrystals alone.

Abstract: Photodiodes configured to convert incident photons in the short-wave infrared (SWIR) to electric current, where the photodiodes have a PbS/PbClx core/shell nanocrystal absorber layer. The PbClx shell in the PbS/PbClx nanocrystals provide native passivation in the (100) crystal facets and enable removal of native ligands and ligand exchange on the (111) crystal facets of the PbS/PbClx nanocrystals such that the photodiode exhibits reduced current densities under reverse bias and greater infrared photoresponse, providing improved device performance as compared to photodiodes having absorber layers formed from PbS core nanocrystals alone.

Abstract: A process for synthesizing Cu2-xS/PbS core/shell nanocrystals. Pb-oleate is mixed with 1-octadecene and heated to 60° C. Cu2-xS core solution and bis(trimethylsilyl)sulfide stock solution are added and the mixture is stirred at 60° C. for 6 minutes to form the PbS shell around the Cu2-xS nanocrystal cores. The flask is cooled and acetonitrile and toluene is added and the mixture is centrifuged to precipitate and remove the Cu2-xS/PbS core/shell nanocrystals from the reaction mixture. The reaction also produces homogeneously nucleated PbS nanocrystals, which are removed from the Cu2-xS/PbS core/shell reaction mixture via size-selective precipitation. By tailoring the amounts of Pb-oleate and bis(trimethylsilyl)sulfide stock solution in the reaction vessel, while maintaining their molar ratio of 1.5:1 and the number of Cu2-xS cores in the reaction, Cu2-xS/PbS core/shell nanocrystals having a predetermined shell thickness of PbS, and thus a predetermined level of chemical stability, can be obtained.