Title :
Effect of InP passivation on carrier recombination in InxGa1-xAs/GaAs surface quantum wells
Author :
Lipsanen, H. ; Sopanen, M. ; Ahopelto, J. ; Sandmann, J. ; Feldmann, J.
Author_Institution :
Optoelectron. Lab., Helsinki Univ. of Technol., Espoo, Finland
Abstract :
Carrier recombination in surface and near-surface InxGa 1-xAs/GaAs quantum wells was studied using time-resolved and cw photoluminescence spectroscopy. Surface passivation by an ultrathin layer (1 ML) of InP was found to yield dramatically enhanced luminescence intensity. A blue shift due to the vacuum barrier on the surface was measured to be as high as 70 meV for a passivated 3 nm thick In0.25Ga0.75As/GaAs surface QW. The carrier recombination dynamics was studied for 7 nm thick In0.10Ga 0.90As/GaAs surface and near-surface QWs. A carrier lifetime of 40 ps was obtained for an unpassivated near-surface QW whereas lifetimes of 300 ps and 245 ps were measured for passivated near-surface and surface QWs, respectively. The results indicate that the passivation reduces the surface recombination remarkably
Keywords :
III-V semiconductors; carrier lifetime; gallium arsenide; indium compounds; passivation; photoluminescence; semiconductor quantum wells; spectral line shift; surface recombination; time resolved spectra; 245 ps; 300 ps; 40 ps; CW photoluminescence; InGaAs-GaAs; InP; InP passivation; blue shift; carrier lifetime; carrier recombination; luminescence intensity; surface quantum wells; surface recombination; time-resolved photoluminescence; ultrathin layer; Epitaxial growth; Epitaxial layers; Gallium arsenide; Indium gallium arsenide; Indium phosphide; Passivation; Photoluminescence; Radiative recombination; Spontaneous emission; Surface morphology;
Conference_Titel :
Indium Phosphide and Related Materials, 1998 International Conference on
Conference_Location :
Tsukuba
Print_ISBN :
0-7803-4220-8
DOI :
10.1109/ICIPRM.1998.712601
