Thermal and nonthermal melting of III-V compound semiconductors

0509922 - ÚFP 2020 RIV US eng J - Journal Article
Medvedev, Nikita - Fang, Z. - Xia, Ch. - Li, Z.
Thermal and nonthermal melting of III-V compound semiconductors.
Physical Review B. Roč. 99, č. 14 (2019), č. článku 144101. ISSN 2469-9950. E-ISSN 2469-9969
R&D Projects: GA MŠMT(CZ) LM2015083
Institutional support: RVO:61389021
Keywords : binding molecular-dynamics * electronic-structure * gallium-arsenide * gaas
OECD category: Condensed matter physics (including formerly solid state physics, supercond.)
Impact factor: 3.575, year: 2019
Method of publishing: Limited access
https://journals.aps.org/prb/abstract/10.1103/PhysRevB.99.144101

We study theoretically the response of group III-V compound semiconductors (AlAs, AlP, GaAs, GaP, GaSb) to free-electron laser irradiation, identifying their damage thresholds. The employed hybrid code XTANT is capable of modeling both thermal and nonthermal effects under ultrafast electronic excitation. It allowed us to reveal common trends in the studied materials: all but the AlAs III-V compounds studied here exhibit a phase transition into a metallic disordered state of lower density than the solid phase via a thermal phase transition. This transition is instigated by electron-ion coupling at doses below the nonthermal melting. Irradiated AlAs showed two possible phases produced: low-density and high-density liquid. We demonstrate that the transferrable tight-binding method within the Born-Oppenheimer approximation significantly overestimates the damage threshold predicting only nonthermal melting in comparison to a non-Born-Oppenheimer scheme, which accounts for both effects and their interplay.
Permanent Link: http://hdl.handle.net/11104/0300512