Title :
High-efficiency light-emitting diodes at /spl ap/1.3 /spl mu/m using InAs-InGaAs quantum dots
Author :
Fiore, A. ; Oesterle, U. ; Stanley, R.P. ; Ilegems, M.
Author_Institution :
Inst. for Micro-Optoelectron., Ecole Polytech. Federale de Lausanne, Switzerland
Abstract :
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.
Keywords :
III-V semiconductors; electroluminescence; excited states; gallium arsenide; indium compounds; light emitting diodes; mirrors; optical transmitters; quantum well devices; self-assembly; semiconductor heterojunctions; semiconductor quantum dots; spontaneous emission; 0.8 percent; 1 percent; 1.3 mum; 1.5 mW; 1285 nm; 13 percent; 298 K; Au; Au mirror; InAs-InGaAs; InAs-InGaAs quantum dots; InGaAs quantum well; LEDs; bidimensional states; excited states; external quantum efficiency; extraction efficiency; high-efficiency light-emitting diodes; high-injection electroluminescence; light-emitting diodes; long-wavelength self-assembled quantum dots; photovoltage spectra; radiative efficiency; reverse bias; room temperature; transition energies; Gallium arsenide; Indium gallium arsenide; Light emitting diodes; Mirrors; Quantum dot lasers; Quantum dots; Substrates; Surface emitting lasers; Temperature; US Department of Transportation;
Journal_Title :
Photonics Technology Letters, IEEE
