Open AccessPhoto-acoustic response and optical features of 2D-TlGaSe2 and GaAs semiconductors
Author(s) -
V. Grivickas,
Karolis Gulbinas,
V. Bikbajevas,
Paulius Grivickas
Publication year - 2021
Publication title -
lithuanian journal of physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.269
H-Index - 16
eISSN - 2424-3647
pISSN - 1648-8504
DOI - 10.3952/physics.v61i2.4439
Subject(s) - semiconductor , materials science , stark effect , optics , band gap , attenuation coefficient , isotropy , laser , thermoelastic damping , optoelectronics , planar , absorption (acoustics) , deformation (meteorology) , stacking , physics , spectral line , computer graphics (images) , nuclear magnetic resonance , astronomy , thermal , meteorology , computer science , composite material
The paper focuses on investigation of the acoustic-optical properties of 2D-TlGaSe 2 and GaAs semiconductors using laser pulses. We present the photo-darkening experiments performed by using CW light in spectral ranges below the band gap of TlGaSe 2 . The data provides evidence that photo-acoustic signals (PAS) for the above band gap are significantly stronger and linear in 2D-TlGaSe 2 while they are distorted by nonlinear processes in isotropic GaAs. The comparison discloses characteristic parameters of TlGaSe 2 , namely a high factor and a negative sign in the refraction coefficient with pressure, a low absorption coefficient and absence of band filling; all guarantee stabile energy conversion by thermoelastic deformation mechanism. Below the band gap range, we found a new kind of PAS in TlGaSe 2 on near surfaces. Likewise, we demonstrate that in such spectral range the giant Stark effect in TlGaSe 2 is created by focused CW beams. The Stark effect produces local optical darkening which can provide explosion at extreme light power. Likely, both effects could be related to the planar stacking faults in 2D-TlGaSe 2 , which produce a spontaneous charge separation on layers.