Intrinsic and Extrinsic Exciton Recombination Pathways in AgInS2 Colloidal Nanocrystals
(a) Normalized PL spectra for AgInS2 NCs at room temperature obtained during three cycles of staircase voltammetry with negative electrochemical potential (): lowered from 0 to -2.4 V and then back to 0 V (150 mV steps, each lasting 10 s). (b) Spectrally integrated and normalized PL intensity as a function of extracted from (a). The applied is reported in background as blue vertical step line. (c) Same as (b) for positive potential increasing from 0 to +1.8 V and then back to 0 V. (d) Schematic of the radiative recombination pathway (red arrow) and the competing nonradiative electron trapping processes (ET) to defect states (DS) shown as grey arrows. The effect of on PL intensity depends on the filling/emptying of DS (right of the band diagram) in response to changes in the position of the Fermi Level (FL) represented as a blue line.