A self-consistent, one-dimensional solution of the Schrodinger and Poisson equations is obtained using the finite-difference method with a nonuniform mesh size. The use of the proper matrix transformation allows preservation of the symmetry of the discretized Schrodinger equation, even with the use of a nonuniform mesh. size, therefore reducing the computation time. This method is very efficient in finding eigenstates extending over relatively large spatial areas without loss of accuracy. For confirmation ofthe accuracy of this method, a comparison is made with the exactly calculated eigenstates of GaAsl AIGaAs rectangular wells. An example of the solution of the conduction band and the electron density distribution of a single-heterostructure GaAsl AIGaAs is also presented. l. iNTRODUCTiON

A truncated-inverted-pyramid (TIP) chip geometry provides substantial improvement in light extraction efficiency over conventional AlGaInP/GaP chips of the same active junction area (∼0.25 mm2). The TIP geometry decreases the mean photon path-length within the crystal, and thus reduces the effects of internal loss mechanisms. By combining this improved device geometry with high-efficiency multiwell active layers, record-level performance for visible-spectrum light-emitting diodes is achieved. Peak efficiencies exceeding 100 lm/W are demonstrated (100 mA dc, 300 K) for orange-emitting (λp∼610 nm) devices, with a peak luminous flux of 60 lumens (350 mA dc, 300 K). In the red wavelength regime (λp∼650 nm), peak external quantum efficiencies of 55% and 60.9% are measured under direct current and pulsed operation, respectively (100 mA, 300 K).

Magnetic and electronic properties of D022-Mn3Ge (001) films Appl. Phys. Lett. 101, 132410 (2012) Magneto-optical spectrum of Mn-doped ZnO nanorods J. Appl. Phys. 112, 044310 (2012) Density matrix treatment of non-adiabatic photoinduced electron transfer at a semiconductor surface J. Chem. Phys. 137, 22A521 (2012) Time-dependent quantum transport: An efficient method based on Liouville-von-Neumann equation for singleelectron density matrix J. Chem. Phys. 137, 044113 (2012) Transport characteristics of AlGaN/GaN/AlGaN double heterostructures with high electron mobility

We have studied the effects of the proximity of a bare Al0.3Ga0.7As surface on the luminescence of an underlying GaAs quantum well (QW) before and after hydrogenation. The mechanism which is affected by H is tunneling to surface states through the surface barrier. Its thickness was varied by wet etching from 60 to 350 Å. Our experiments reveal that the degradation of luminescence efficiency from the QW is dependent on the surface barrier thickness and the excitation energy used in the photoluminescence measurements. A complete recovery or even further enhancement of luminescence efficiency was observed in the near-surface QW after low-energy ion-beam hydrogenation, even at room temperature.

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