Suppressed carrier scattering in cadmium sulfideencapsulated lead sulfide nanocrystal films

One of the main problems on the development of efficient nanocrystal devices is the weak strategy to deposit colloidal nanocrystals into films. The current work demonstrates the comparative study of the several mechanisms to make nanocrystal films with the use of all-optical approach to examine the dynamics of the electron transport process. The mechanism of carrier scattering on trap states/defects is distinguished exclusively from other charge or energy transfer processes through exciton dissociation by measuring the lifetimes for excited charges in matrix encapsulated or ligand linked PbS nanoparticle solids, featuring a varying amount of ZnS nanocrystals. The carrier mobility and the diffusion lengths for all types of solids within the hoping transport regime were then estimated using the measured lifetimes. The matrix capped nanoparticle solids have shown a smaller probability for the carrier scattering than that of nanoparticle films cross linked with 1,2-ethanedithiol molecule or 3-mercaptopropionic acid. The density of the traps on the surface of nanoparticles/matrix interfaces are comparatively lower due to the suppressed charge scattering in matrix capped nanoparticle films.