Intrinsic and Extrinsic Exciton Recombination Pathways in AgInS2 Colloidal Nanocrystals
(a) Representative set of PL spectra of AgInS2 NCs under pulsed laser excitation at 3.5 eV (355 nm) with 150 Hz repetition rate progressively lowering temperature from 300 K to 3.5 K (from red to blue: 300, 200, 100, 3.5 K). (b) Spectrally integrated and normalized PL intensity from (a) and corresponding . The solid black line represents the fit with the equation described in the text (). (c) Decay curves for PL maximum at decreasing temperature from 300 to 3.5 K under 3.5 eV (355 nm) excitation at 150 Hz repetition rate. Inset: three-level model of grey (G) and dark (D) exciton states separated in energy by . (d) PL decay lifetimes extracted from (c) as a function of temperature together with the respective fit (black line) to Equation (1). (e) PL decay curves for Ag:CdSe NCs at decreasing temperature from 300 K to 4 K (from blue to grey) collected at Ag-related PL maximum (1.69 eV) under pulsed laser excitation at 3.5 eV (355 nm) with 500 Hz repetition rate. (f) PL decay lifetimes extracted from (e) as a function of temperature.