ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
High-pressure studies on high quality AlxGa1−xAs double heterostructure light emitting diodes (LEDs) grown by liquid phase epitaxy (LPE) are presented. The AlxGa1−xAs active region varies in composition from x∼0.25 to x∼0.53, i.e., through the important region of the direct-indirect crossover (x≡xc≈0.45). The pressure coefficient of the Γ conduction band is observed to decrease (∼1 meV/kbar for x∼0.25 to x∼0.53) with increasing Al concentration, which is in accord with alloy disorder and band-edge bowing. Indirect-gap (X) recombination radiation of significant intensity is observed and provides evidence for the high quality of the LPE diodes. High-pressure measurements, and the corresponding increase in energy of the direct band edge and decrease in the indirect band edge, show that the light emission is a strong function of the carrier distribution in the Γ and X conduction-band minima. Comparison LEDs fabricated from a crystal (x∼0.37) grown by metalorganic chemical vapor deposition exhibit nearly similar behavior as the LPE LEDs with application of pressure but with an order of magnitude lower light emission.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.334446
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