1. “Quantum Mechanics in Our Lab.”
Optoelectronics and Semiconductors Laboratory
김중철, 조소연, 한송희

2. Introduction to Laboratory Raman spectroscopy 3. Photoluminescence
Table of contents
Introduction to Laboratory
Raman spectroscopy
3. Photoluminescence

3. 1. Introduction to Laboratory

5. Introduction to Laboratory
Graphene
Solar Cell
2-dimensional (2D) honeycomb lattice consisting of carbon atoms
Semiconductors which convert Sun light into electricity
Raman spectroscopy, Photoluminescence

6. 2. Raman spectroscopy

7. Raman spectroscopy
〮In the Raman effect a photon is scattered inelastically by a crystal, with creation or annihilation of a phonon.
Rayleigh
Anti-Stokes
Stokes
Virtual state
u=0 1 2

8. Phonon
〮 Phonon → quantized elastic wave 〮simple model of phonon linear lattice of particles connected by springs.

9. Phonon

10. Phonon
Optical The atoms vibrate against each other, but their center of mass is fixed. Acoustic The atoms move together.
Raman probes k=0 because of the very small
momentum of photon

11. Example of Raman spectrum
-Raman spectrum of single crystal CZTSe

12. 3. Photoluminescence

13. Photoluminescence (PL)

14. Photoluminescence (PL)
〮Solution of Hamiltonian
DFT(Density Functional Theory)
Tight binding
First principle
k·p perturbation theory

15. Tight binding model in 1D

16. Application of PL
GaAs band structure
Diatomic crystal
(2 atoms per unit cell)

17. Thanks for your attention! Q&A