# Exciton-Related Raman Scattering, Interband Absorption and Photoluminescence in Colloidal CdSe/CdS Core/Shell Quantum Dots Ensemble

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## Abstract

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## 1. Introduction

## 2. Exciton States

## 3. Optical Properties

## 4. Results and Discussion

## 5. Conclusions

## Author Contributions

## Funding

## Conflicts of Interest

## References

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**Figure 1.**The schematic plot of CdSe/CdS core/shell QD (

**a**) with corresponding energy band structure (

**b**).

**Figure 2.**The dependence of the exciton energy on the halfwidth for the first three levels. Dots correspond to the values obtained by the numerical calculations. The lines correspond to the fitted curve which has been fitted to the calculated data points. The following model for the curve was selected: ${E}_{n}={A}_{n}+\frac{{B}_{n}}{\beta}+\frac{{C}_{n}}{{\beta}^{2}}$.

**Figure 3.**The dependence of the absorption spectra on the energy of incident light for different sizes of CdSe/CdS core/shell QD (

**a**) for single QD, (

**b**) for the ensemble of QDs.

**Figure 4.**The dependence of the PL spectra light energy for different sizes of CdSe/CdS core/shell QD (

**a**) for single QD, (

**b**) for the ensemble of QDs.

**Figure 5.**Exciton-related Raman DCS as a function of secondary-radiation photon energy for different sizes of CdSe/CdS core/shell QD, (

**a**) for single QD, inset: three-level scheme, (

**b**) for the ensemble of QDs.

**Table 1.**This dimensionless numerical values for the parameters ${A}_{n}$, ${B}_{n}$ and ${C}_{n}$. All of the energies have been presented in Rydberg energy ${E}_{R}$ and all lengths in Bohr radius ${a}_{B}$. For the Rydberg, energy is equal to ${E}_{R}=18.85\text{}\mathrm{meV}$, and Bohr radius is ${a}_{B}=2.98\text{}\mathrm{nm}$.

$\mathit{n}$ | ${\mathit{A}}_{\mathit{n}}/{\mathit{E}}_{\mathit{R}}$ | $\left({\mathit{B}}_{\mathit{n}}{\mathit{a}}_{\mathit{B}}\right)/{\mathit{E}}_{\mathit{R}}$ | $\left({\mathit{C}}_{\mathit{n}}{\mathit{a}}_{\mathit{B}}^{2}\right)/{\mathit{E}}_{\mathit{R}}$ |
---|---|---|---|

1 (i) | −1.816 | 60.339 | −3.338 |

2 (f) | −1.809 | 71.940 | −5.873 |

3 (a) | −1.886 | 84.390 | −11.360 |

**Table 2.**Dimensionless numerical values for the parameters ${A}_{n}$, ${B}_{n}$ and ${C}_{n}$. All of the energies have been presented in Rydberg energy ${E}_{R}$ and all lengths in Bohr radius ${a}_{B}$. For the Rydberg energy is equal to ${E}_{R}=18.85\text{}\mathrm{meV}$, and Bohr radius is ${a}_{B}=2.98\text{}\mathrm{nm}$.

$\mathit{\beta}=3\text{}\mathbf{nm}$ | $\mathit{\beta}=4\mathbf{nm}$ | $\mathit{\beta}=5\text{}\mathbf{nm}$ | $\mathit{\beta}=6\text{}\mathbf{nm}$ | |
---|---|---|---|---|

${\tau}_{exc}$, ps | 367 | 487 | 610 | 736 |

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**MDPI and ACS Style**

Mantashian, G.A.; Mantashyan, P.A.; Sarkisyan, H.A.; Kazaryan, E.M.; Bester, G.; Baskoutas, S.; Hayrapetyan, D.B.
Exciton-Related Raman Scattering, Interband Absorption and Photoluminescence in Colloidal CdSe/CdS Core/Shell Quantum Dots Ensemble. *Nanomaterials* **2021**, *11*, 1274.
https://doi.org/10.3390/nano11051274

**AMA Style**

Mantashian GA, Mantashyan PA, Sarkisyan HA, Kazaryan EM, Bester G, Baskoutas S, Hayrapetyan DB.
Exciton-Related Raman Scattering, Interband Absorption and Photoluminescence in Colloidal CdSe/CdS Core/Shell Quantum Dots Ensemble. *Nanomaterials*. 2021; 11(5):1274.
https://doi.org/10.3390/nano11051274

**Chicago/Turabian Style**

Mantashian, Grigor A., Paytsar A. Mantashyan, Hayk A. Sarkisyan, Eduard M. Kazaryan, Gabriel Bester, Sotirios Baskoutas, and David B. Hayrapetyan.
2021. "Exciton-Related Raman Scattering, Interband Absorption and Photoluminescence in Colloidal CdSe/CdS Core/Shell Quantum Dots Ensemble" *Nanomaterials* 11, no. 5: 1274.
https://doi.org/10.3390/nano11051274