Topics

1

General Questions and Answers / silicon raman peak shifting /phonon band at higher Temperature

« on: June 3, 2025, 09:37 »

To simulate the thermal effects on the Raman peak shift (or phonon band) of silicon, the typical approach involves DFT + MD simulations (e.g., VASP + DynaPhoPy https://www.sciencedirect.com/science/article/pii/S0010465517302631#b5, or Quantum ESPRESSO + Phono3py). Since QuantumATK is based on Quantum ESPRESSO, it is also possible to perform MD simulations using FF Calculator with empirical potentials (e.g., Tersoff).

I would like to achieve a similar simulation—specifically, the temperature-induced shift of the Raman peak. I am currently using QuantumATK version 2023.12-SP1.

Could you please provide some guidance, example scripts, or options within QuantumATK that would help me carry out such a simulation? Thanks.

2

General Questions and Answers / How to fit the optical constants of silicon?

« on: September 25, 2024, 07:13 »

I tried using the silicon alpha data to simulate the optical constants of silicon from the paper by D. E. Aspnes and A. A. Studna: Dielectric functions and optical parameters of Si, Ge, GaP, GaAs, GaSb, InP, InAs, and InSb from 1.5 to 6.0 eV (Phys. Rev. B 27, 985-1009, 1983), but I found that the results did not match well.
Are there any methods to improve this? Thank you.