Power-Dependent and Ultrafast Spectroscopic Studies of Ag Ions Doped Colloidal CdSe Nanoplatelets

Atomically precise two-dimensional (2D) semiconductor nanoplatelets (NPLs) are found to be promising materials for next-generation optoelectronic devices due to their excellent optical properties. However, energy loss through phonon emission significantly causes problems in achieving efficient performance. Power-dependent steady-state spectroscopy and ultrafast spectroscopic studies have been performed to understand the influence of Ag ions on ultrafast carrier dynamics and thermalization processes in colloidal CdSe NPLs. An ultrafast transient absorption spectroscopic study shows that the rise time is faster from 410 fs to ∼160 fs after 11% Ag doping in CdSe NPLs. The dopant states act as a trap for the charge carriers that facilitate faster relaxation of electrons in these dopant states. The bleach decay time constant (