The Role of Physical Models in the Description of Luminescence Kinetics of Hybrid Nanowires

Influence of TOPO and TOPO-CdSe/ZnS Quantum Dots on Luminescence Photodynamics of InP/InAsP/InPHeterostructure Nanowires

“…The values presented in the Table 1 were calculated using the approximation by the function of the sum of two exponentials, which is widely known for describing various kinetic processes [ 9 , 18 , 19 ]: I lum = A 1 × exp(−t/t 1 ) + A 2 × exp(−t/t 2 ), Here, I lum is PL decay intensity normalized to unity at the initial moment of time; t i is PL decay time components, and A i is their corresponding amplitudes. The condition for the amplitudes is the next: A 1 + A 2 = 1.…”

“…The condition for the amplitudes is the next: A 1 + A 2 = 1. The use of this function is quite universal, and, as shown in [ 9 ], it makes it possible to characterize the radiating state by the number of main feeding channels. To calculate the average lifetime, we used the formula <t> = ∑A i × t i , taking into account the presence of FRET in the system [ 8 , 9 ].…”

“…The use of this function is quite universal, and, as shown in [ 9 ], it makes it possible to characterize the radiating state by the number of main feeding channels. To calculate the average lifetime, we used the formula <t> = ∑A i × t i , taking into account the presence of FRET in the system [ 8 , 9 ]. It can be seen from Table 1 that upon excitation at 635 nm wavelength, the kinetics of both InAsP QI and QW had two luminescence decay components with similar decay times: t 1 = 4–6 ns and t 2 = 25–30 ns (the average lifetime is about 10–12 ns).…”

“…The faster component t 1 corresponded to direct transition of the InAsP nanoinsertions, and the long-term t 2 corresponded to the contributions of other channels of excitation energy exchange (population of excited states through electron-phonon and trapped states in the region of the InAsP/InP heterojunction, diffusion of electron-hole pairs (excitons) arising upon excitation of the InP NW shell, and processes at the NW-TOPO-QDs interface). Without passivation, an increase in temperature only led to a significant reduction in the long-term component t 2 of the QW due to thermal exchange and, accordingly, in the average QW lifetime from 10 to 3 ns [ 9 ]. The deposition of low concentration TOPO led to an increase in t 2 for QI and QW, which decreased with increasing temperature.…”

“…We have recently shown [ 8 , 9 ] that the deposition of a TOPO quasi-Langmuir layer containing CdSe/ZnS colloidal dots on the arrays of InP/InAsP/InP nanowires leads to a significant increase in the duration and intensity of the photoluminescence of the InAsP quantum dot like nanoinsertion (QI). This work aimed to shed more light onthe study of the luminescence photodynamics of the InP/InAsP/InP NWs ensemble passivated by TOPO ligands and by TOPO-CdSe/ZnS quantum dots (QD) layers under excitation close to the absorbance band of CdSe/ZnS QDs and in its transparent region.…”