We study the influence of an in-plane magnetic field and Coulomb interactions on physics quantum spin Hall insulators, like those in InAs/GaSb HgTe/CdTe wells. Using a Hartree-Fock mean-field theory approximation, we calculate phase diagrams as functions band gap, hybridization, strength. show that when hybridization is weak, system unstable against formation density-wave states. As strength in...

The direct band gap of monolayer semiconducting transition-metal dichalcogenides (STMDs) enables a host of new optical and electrical properties. However, bilayer STMDs are indirect band gap semiconductors, which limits its applicability for high-efficiency optoelectronic devices. Here, we report that the direct band gap can be achieved in bilayer MoSe2-WSe2 lateral heterostructures by alternat...

High-frequency (optical) and low-frequency (static) dielectric constant versus band gap trends, as well as index of refraction versus band gap trends are plotted for 107 inorganic semiconductors and insulators. These plots are describable via power-law fitting. Dielectric screening trends that emerge from this analysis have important optical and electronic implications. For example, barrier low...

Device modeling and simulation studies of a Cu(In1-x,Gax)Se2 (CIGS) thin film solar cell have been carried out. A variety of graded band-gap structures, including space charge region (SCR) grading, back surface region grading, and double grading of the CIGS absorber layer, are examined. The device physics and performance parameters for different band-gap profiles were analyzed. Based on the sim...

In this work, we study the disorder effects on bulk-boundary correspondence of two-dimensional higher-order topological insulators (HOTIs). We concentrate two cases: (i) bulk-corner correspondence, (ii) edge-corner correspondence. For case, demonstrate existence mobility gaps and clarify related invariant that characterizes gap. Furthermore, find that, while system preserves in presence disorde...

We present a first principle investigation of the electronic structure and the band gap bowing parameter of zinc-blende AlxGa1−xN using both local density approximation and screened-exchange density functional method. The calculated sX-LDA band gaps for GaN and AlN are 95% and 90% of the experimentally observed values, respectively, while LDA underestimates the gaps to 62% and 70%. In contrast ...