Energy Material Advances / 2021 / Article / Fig 4

Research Article

Intrinsic and Extrinsic Exciton Recombination Pathways in AgInS2 Colloidal Nanocrystals

Figure 4

(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.