Light-emitting diodes (LEDs) based on long-wavelength, self-assembled InAs-InGaAs quantum dots (QDs) are demonstrated and characterized. The LEDs consist of a single layer of QDs positioned at /spl lambda//2 from a top gold mirror to enhance the extraction efficiency. The external quantum efficiency at room temperature is 1%, which corresponds to an estimated 13% radiative efficiency. High-injection electroluminescence and photovoltage spectra under reverse bias allow us to determine the transition energies of excited states in the QDs and bidimensional states in the adjacent InGaAs quantum well.
Published in:
Photonics Technology Letters, IEEE
(Volume:12
,
Issue:
12
)
Date of Publication: Dec. 2000