Investigation of Magnetic Circular Dichroism Spectra of Semiconductor Quantum Rods and Quantum Dot-in-Rods

Abstract

Anisotropic quantum nanostructures have attracted a lot of attention due to their unique properties and a range of potential applications. Magnetic circular dichroism (MCD) spectra of semiconductor CdSe/ZnS Quantum Rods and CdSe/CdS Dot-in-Rods have been studied. Positions of four electronic transitions were determined by data fitting. MCD spectra were analyzed in the A and B terms, which characterize the splitting and mixing of states. Effective values of A and B terms were determined for each transition. A relatively high value of the B term is noted, which is most likely associated with the anisotropy of quantum rods.

Effective Mass for Holes in Paramagnetic, Plasmonic Cu5FeS4 Semiconductor Nanocrystals

“…The deconvolution of peaks is formed by the summation of a Gaussian curve representing C 0 and B 0 terms and the derivative of a Gaussian curve representing the A 1 term modeled after previous literature. 66 The assigned electronic transitions in the MCD at 1.12 (LSPR), 1.19 (IB-I), 1.77 (IB-II), and 3.44 (CB) eV are identified through secondorder derivation of the linear absorption spectrum in tandem with the most probable computationally identified electronic transitions. For the fits, the normalized transition dipole moments were obtained as indicated previously by Safin et al 66 The assumption of a B 0 contribution and a convolved A 1 -: C 0term reflect the known magnetic ground state in 5:1 bornite and the difficulty to deconvolve the MCD spectra fully.…”

“…66 The assigned electronic transitions in the MCD at 1.12 (LSPR), 1.19 (IB-I), 1.77 (IB-II), and 3.44 (CB) eV are identified through secondorder derivation of the linear absorption spectrum in tandem with the most probable computationally identified electronic transitions. For the fits, the normalized transition dipole moments were obtained as indicated previously by Safin et al 66 The assumption of a B 0 contribution and a convolved A 1 -: C 0term reflect the known magnetic ground state in 5:1 bornite and the difficulty to deconvolve the MCD spectra fully. MCD parameters for the identified transitions are listed in Table 1.…”

“…The VH-MCD spectra in Figure A can be evaluated in terms of the A 1 - (Zeeman term), B 0 - (field-induced state mixing), and C 0 - (ground state degeneracy due to paramagnetic state) terms (eq ). where Δ D MCD ( E ) is the MCD spectrum, E = h ν for photon energy, γ is an oscillator strength constant, f ( E ) is the linear absorption spectra normalized by area, k B T is the Boltzmann constant and temperature product, μ B is the Bohr magneton, H is the field strength, c is the concentration, and z is the pathlength. , The 5:1 bornite is magnetic and may have C 0 -term contribution. The coupled structural and magnetic phase transition below 67 K may impact the value of C 0 .…”

“…In Figure , the experimental data are fitted to a convolved A 1 : C 0 and B 0 term. The deconvolution of peaks is formed by the summation of a Gaussian curve representing C 0 and B 0 terms and the derivative of a Gaussian curve representing the A 1 term modeled after previous literature . The assigned electronic transitions in the MCD at 1.12 (LSPR), 1.19 (IB-I), 1.77 (IB-II), and 3.44 (CB) eV are identified through second-order derivation of the linear absorption spectrum in tandem with the most probable computationally identified electronic transitions.…”

Chitosan nanocomposites with CdSe/ZnS quantum dots and porphyrin

“…4a have shown a series of bands, including A and B terms, and reflected the diamagnetic properties of CdSe QDs. 51 MCD spectra of free TPP monomers in CCl 4 ( Fig. 4b ) comprise two opposite-signed symmetrical bands centered at 416 nm and 425 nm due to Zeeman splitting of the Soret band.…”