Title :
Growth and characterization of a bound-to-quasi-continuum QWIP with Al-graded triangular confinement barriers
Author :
Guzman, A. ; Sanchez-Rojas, J.L. ; Tijero, J.M.G. ; Hernando, J. ; Calleja, E. ; Munoz, Eugenio ; Vergara, G. ; Almazan, R. ; Gomez, L.J. ; Verdu, M. ; Montojo, M.T.
Author_Institution :
Dept. de Ingenieria Electron., ETSI Telecommun., Madrid, Spain
Abstract :
A bound-to-quasi-continuum GaAs-AlGaAs quantum-well infrared photodetector (QWIP) with absorption peak centered at 9 μm has been grown and characterized. Instead of the abrupt interfaces between AlGaAs layers, a different configuration based on AlGaAs graded triangular barriers is used in this work. This structure allows one to grow all the layers with one single Al cell avoiding growth interruption. The detectors show symmetric behavior in the current versus voltage characteristic. Peak responsivities as high as 0.5 A/W using a tilted substrate holder and without any light coupling mechanism were measured. Besides, photocurrent response in normal incidence, without diffraction grating, was also observed.
Keywords :
III-V semiconductors; aluminium compounds; diffraction gratings; gallium arsenide; infrared detectors; molecular beam epitaxial growth; optical fabrication; semiconductor growth; semiconductor quantum wells; 9 mum; Al cell; Al-graded triangular confinement barriers; AlGaAs layer; GaAs-AlGaAs; abrupt interfaces; absorption peak; bound-to-quasi-continuum GaAs-AlGaAs quantum-well infrared photodetector; bound-to-quasi-continuum QWIP; current versus voltage characteristic; diffraction grating; growth interruption; light coupling mechanism; normal incidence; peak responsivities; photocurrent response; symmetric behavior; tilted substrate holder; Carrier confinement; Diffraction; Electromagnetic wave absorption; Infrared detectors; Optical coupling; Photoconductivity; Photodetectors; Quantum wells; Substrates; Voltage;
Journal_Title :
Photonics Technology Letters, IEEE
