The role of spontaneous and piezoelectric polarization in III–V nitride heterostructure devices is discussed. Problems as well as opportunities in incorporating polarization in abrupt and graded heterojunctions composed of binary, ternary, and quaternary nitrides are outlined. 1 Introduction Spontaneous polarization exists along the (0001) (metal-polar) and ð0001Þ (N-polar) directions of wurtzi...

A complete semi-analytical model is proposed for the simulation of the electronic, mechanical and piezoelectric properties of narrow gap strained semiconductor quantum nanostructures. A transverse isotropic approximation for the strain and a new axial approximation for the strained 8x8 Hamiltonian are proposed. It is applied extensively to the case of InAs/InP quantum dots (QD). Symmetry analys...

Efficient actuation is crucial to obtaining optimal performance from nanoelectromechanical systems (NEMS). We employed epitaxial piezoelectric semiconductors to obtain efficient and fully integrated NEMS actuation, which is based on exploitation of the interaction between piezoelectric strain and built-in charge depletion. The underlying actuation mechanism in these depletion-mediated NEMS beco...

In our work, a monolithic integration of RF filter SAW, on a semiconductor substrate such us Si or GaAs is highly desirable to miniaturize the outer dimensions and introduce the new functionalities of the cellular phones. But, direct monolithic integration of SAW filters is impossible with Si which is non piezoelectric and difficult with GaAs which is weakly piezoelectric. One alternative is th...

Ambient energy harvesting using piezoelectric nanomaterials is today considered as a promising way to supply microelectronic devices. Since the first demonstration of electrical energy generation from piezoelectric semiconductor nanowires in 2006, the piezoelectric response of 1D-nanostructures and the development of nanowirebased piezogenerators have become a hot topic in nanoscience. After se...

Films of hafnium oxide (HfO 2 ) were synthesized on a silicon substrate by magnetron sputtering target with similar composition. The results studies the structural composition HfO films and electrical properties metal-insulator-semiconductor (Ni-HfO_2-n-Si) structures are presented Keywords: Metal-dielectric-semiconductor (MDS) structures, ferroelectric films, piezoelectric response, microstruc...

is among the most abundant and reliable energy sources in our daily life, regardless of weather or temperature conditions, in contrast with solar [ 2 ] and thermoelectric energies. [ 3 ] New materials, structures and technologies have been subjects of active research and development. [ 4–7 ] Likewise, at the nanoscale, energy harvesting nanotechnologies based on the piezoelectric effect have be...

We have calculated the piezoelectric coupling between a two-dimensional electron gas and the stress field due to a lateral surface superlattice, a periodic striped gate. The stress is assumed to arise from differential contraction between the metal gate and semiconductor. The piezoelectric potential is several times larger than the deformation potential and generally gives the dominant coupling...

We have developed a model for the impact of the hydrogen-induced piezoelectric effect on the threshold voltage of InP HEMTs and GaAs PHEMTs. We have used two-dimensional (2-D) finite element simulations to calculate the mechanical stress caused by a Ti-containing metal gate that has expanded due to hydrogen absorption. This has allowed us to map the 2-D piezoelectric charge distribution in the ...

Propagation of extensional waves in a piezoelectric semiconductor rod" We studied the propagation of extensional waves in a thin piezoelectric semiconductor rod of ZnO whose c-axis is along the axis of the rod. The macroscopic theory of piezoelectric semiconductors was used which consists of the coupled equations of piezoelectricity and the conservation of charge. The problem is nonlinear becau...