Effect of the built-in electric field on optical and electrical properties of AlGaAs/InGaAs/GaAs P-HEMT nanoheterostructures

Determination of surface electric potential by photoreflectance spectroscopy of HEMT heterostructures

“…(NH 4 ) 2 S x [1], Si [2] and organic self-assemble monolayer (SAM) [3] have been used for coating GaAs-based devices. The effect of the surface on the electronic properties of a 2DEG has been studied by classic and quantum Hall effect measurements [3,4]. Specifically, the relationship between the surface and internal electric fields with electron mobility is the most important, but this option is not the best one because the structure has to be perturbed with the electrical contacts.…”

Quantum and transport scattering times in AlGaAs/InGaAs nanoheterostructures with AlAs inserts in the spacer layer

“…The samples were mounted in a holder and kept at T = 77 K. PL was excited by a continuous wave focused He-Ne laser radiation (632.8 nm) with excitation power up to 50 mW. The luminescence response in a spectral range 1.2 < ћω < 1.6 eV was detected by a cooled photomultiplier with S1-response [22]. The uncooled Hamamatsu InGaAs photodiode with a lock-in voltmeter was used.…”

“…Twodimensional electron gas (2DEG) confined to a quantum well (QW) InGaAs demonstrates both high electron mobility and drift velocity. The most important factors that limit electron mobility μ e in HEMT are the polar optical phonon scattering [1,22] and remote ionized impurity scattering [3]. In order to improve μ e one should vary the design of the heterostructure, in particular the QW and the barrier layer.…”

Application of BiFeO3 and Bi4Ti3O12 in ferroelectric memory, phase shifters of a phased array, and microwave HEMTs

“…For operation at microwave frequencies (approxi mately hundreds of gigahertz, submillimeter range, λ = 1 mm, ν = 300 GHz), use is currently made of AlGaAs/InGaAs/GaAs rather expensive heterostruc tures with an InP substrate [79] and heterostructures based on (Al,Ga,In)N wide band gap semiconduc tors [80] with working temperatures of up to 1000°C and a specific power of up to 5 W/mm. The high work ing frequencies of such p HEMTs (pseudomorphic high electron mobility transistors) are due to the use of a high mobility two dimensional electron gas (2D EG) in the transistor channel.…”