Experimental evidence of temperature dependent effective mass in AlGaN/GaN heterostructures observed via THz spectroscopy of 2D plasmons

Abstract

Temperature-dependent effective mass in AlGaN/GaN heterostructures was experimentally observed via THz time domain spectroscopy of 2D plasmons in the range of 80–300 K. Grating couplers with different periods and filling factors were developed in order to monitor the behavior of plasma resonances in transmission spectra in the frequency range of 0.5–3.5 THz. For the grating with a 50% filling factor, the fundamental modes were excited and observed at temperatures below 225 K. The change of the filling factor to 80% led to the excitation of the fundamental and second order plasma harmonics observable up to 300 K and 220 K, respectively. Moreover, with an increase in temperature, the 2D plasmons experienced the red-shift in transmission power and phase spectra of all samples. This phenomenon was explained by the renormalization of effective mass, which started distinctly to deviate at 134 K temperature and at 295 K increased up to 55% of its nominal value. The THz spectroscopy of 2D plasmons further confirms a temperature-dependent effective mass in AlGaN/GaN heterostructures as reported previously in optical Hall effect studies.

AlGaN/GaN on SiC Devices without a GaN Buffer Layer: Electrical and Noise Characteristics

“…The obtained N dependence on the parameter W is shown in Figure 5 b. The density of 2DEG was found to be N G -2 DEG = 0.69 × 10 13 cm −2 at 300 K. This density is smaller than that found from the Hall measurements due to depletion by the Schottky barrier built-in voltage [ 29 , 30 ].…”

Intriguing electronic, optical and photocatalytic performance of BSe, M2CO2monolayers and BSe–M2CO2(M = Ti, Zr, Hf) van der Waals heterostructures

“…20,21 To date, a great deal of vdW heterostructures have been studied theoretically [22][23][24][25][26][27] and perceived experimentally. [28][29][30][31] These vdW heterostructures are also utilized to create electronic and optoelectronic devices with novel physical properties and applications. [32][33][34][35][36][37] MXenes-based vdW heterostructures, such as MXenes-MXenes, 38 MXene and nitrogen-doped graphene, 39 MXenes-TMDCs, 40 MXene-blue phosphorene, 41 MXenes and B-doped graphene, 42 have already been fabricated and investigated in detail.…”

Intriguing interfacial characteristics of the CS contact with MX2 (M = Mo, W; X = S, Se, Te) and MXY ((X ≠ Y) = S, Se, Te) monolayers

“…23,24 In this regard, the stackings of semiconductors with semiconductors (SS contact) and metals with semiconductors (MS contact) are of crucial importance, with a wide range of device applications. 25 To date, many of the vdWH in the form of SS contacts have been investigated both theoretically [26][27][28][29][30][31][32][33][34][35][36][37] and experimentally [38][39][40][41] for novel extraordinary applications in optoelectronic devices. [42][43][44][45][46][47] In the case of MS contacts, the Schottky barrier (SB) is an energy barrier across the junction for the transport of carriers.…”