Pyroelectric properties of Al(In)GaN/GaN hetero- and quantum well structures

Abstract

The macroscopic nonlinear pyroelectric polarization of wurtzite Al x Ga 1−x N, In x Ga 1−x N and Al x In 1−x N ternary compounds (large spontaneous polarization and piezoelectric coupling) dramatically affects the optical and electrical properties of multilayered Al(In)GaN/GaN hetero-, nanostructures and devices, due to the huge built-in electrostatic fields and bound interface charges caused by gradients in polarization at surfaces and heterointerfaces. Models of

The Influence of AlGaN Barrier-Layer Thickness on the GaN HEMT Parameters for Space Applications

“…According to the recommendations from the working [4], we have optimized the used mathematical models for the analysis of our heterostructures working. We have chosen two-dimensional hydrodynamical mathematical model, that often is used in many industrial simulation systems [5,6], which, combining with the original physical models of the behavior of electrons in dielectrics and semiconductors, gave the good results.…”

“…In the area at the age of the gate stock, the field intensity can reach many megavolts per centimeter. However, this inevitably leads to the appearance inverse piezoelectric effect in the thin barrier layer that can cause significant mechanical stresses at the surface and in the bulk structure [4,24]. The appearance of the inverse piezoelectric effect is especially dangerous in a strong electric field.…”

Macroscopic Polarization Effect on Bowing Constant of Thermal Parameters of In x Ga1−x N

“…On the basis of these results, one can expect equivalent enhancement in various material parameters and the thermal conductivity of nitride alloys due to the polarization mechanism also. It was established that, similar to the behavior of the spontaneous and piezoelectric polarizations in In x Ga 1Àx N, 14,16,17 the bandgap of these alloys depends on the In content. 36 To describe the effect of strain in the framework of continuum elasticity theory, knowledge of the lattice parameters and elastic constants of In x Ga 1Àx N alloys is needed.…”

“…The existence of these fields in III-V nitrides has been confirmed by both first-principles calculations and experiments. [12][13][14][15][16][17][18][19][20][21] Calculated and experimental results show that two-dimensional electron gases (2DEGs) are generated by spontaneous and piezoelectric polarization effects with sheet resistivity suitable for high-electron-mobility transistors without doping of the barrier layer. 22 These fields significantly influence the distribution and lifetime of excess carriers in InGaN QWs and can have an important impact on the performance of InGaN/GaN-based optoelectronic devices.…”

Effect of non-abrupt doping and interfacial profiles on the carrier sheet density in one-side modulation-doped GaN/AlGaN quantum wells

“…where L w (L b ) is the well (barrier) width, F w (F b ) is the magnitude of the electric field in the well (barrier), and ∆E c is the GaN-AlGaN conduction-band offset, assumed to be given by [16,17], where [18] …”