HERNÁNDEZ, ANTONIA E HIJA [Material gráfico]

Copia digital. Madrid : Ministerio de Educación, Cultura y Deporte, 201

MARZO, LUIS [Material gráfico]

Copia digital. Madrid : Ministerio de Educación, Cultura y Deporte, 201

OJEDA, FERNANDO [Material gráfico]

Copia digital. Madrid : Ministerio de Educación, Cultura y Deporte, 201

High-efficiency top-emitting microcavity LEDs on GaAs and GaAs Si substrates

Microcavity light-emitting diodes (MCLEDs) with top-emitting geometry have been grown by molecular beam epitaxy on GaAs and Si substrates. External quantum efficiencies of up to 10% were obtained for 420 x 420 mu m(2) homoepitaxial devices. The efficiency of 32 x 32 mu m(2) diodes was 4% for homoepitaxial devices and 1% for diodes realized on conformal GaAs-on-Si stripes. Much lower efficiencies were obtained for devices grown directly on GaAs-on-Si seed layers, demonstrating that the conformal epitaxy technique leads to an improvement of the GaAs-on-Si materials quality. These results underline the promise of the conformal epitaxy approach for the realization of monolithically integrated light emitters on silicon substrates. (C) 1999 Elsevier Science B.V. All rights reserved

Low threshold high-power room-temperature continuous-wave operation diode laser emitting at 2.26 μm

International audienceDiode lasers emitting at 2.26 μm, based on the InGaAsSb-AlGaAsSb materials system, are reported. These devices exhibit high internal quantum efficiency of 78% and low threshold current density of 184.5 A/cm2 for a 2-mm-long cavity. Output power up to 700 mW (≈550 mW) has been obtained at 280 K (300 K) in continuous-wave operation with 100 μm×1 mm lasers. These devices have been coated with an antireflection on the output facet and are mounted epilayer down on a copper block. The working temperature was maintained by a thermoelectric Peltier cooling element

NAVARRO, MARGARITA Y HERMANO [Material gráfico]

Copia digital. Madrid : Ministerio de Educación, Cultura y Deporte, 201