We have studied space-charge-induced optical nonlinearities for asymmetric coupled quantum wells. By the spatial separation of heavy holes and electrons, an electrostatic potential is induced which increases the fundamental bandgap. Calculations, using the Hartree approximation, for oqtimi5ed AlGaAs structures show that a blue-shift of the band gap of 9 meV at a carrier density of 10 * cm can b...

Temperature and injection current dependence of electroluminescence (EL) spectral intensity of the super-bright InGaN single quantum well (SQW) light emitting diodes (LED’s) has been carefully investigated over a wide temperature range (T = 15-300 K) and as a function of injection current level (0.1-10 mA). It is found that, when T is decreased slightly to 140 K, the EL intensity efficiently in...

A planar phase space having both position and momentum noncommutativity is defined in a more inclusive setting than that considered elsewhere. The dynamics of a particle in a gravitational quantum well in this space is studied. The use of the WKB approximation and the virial theorem enable analytic discussions on the effect of noncommutativity. Consistent results are obtained following either c...