Title :
A study on the negative photoresponse of AlGaAs/GaAs MODFETs
Author :
Romero, M.A. ; Herczfeld, P.R.
Author_Institution :
Drexel Univ., Philadelphia, PA, USA
Abstract :
A model for the mechanism of negative photoresponse, i.e. the decrease of drain current under illumination, in AlGaAs/GaAs MODFETs (modulation-doped field--effect transistors) is presented. A comprehensive experimental study examining the dependence of this phenomena on gate-to-source bias voltage and optical power is also reported. The negative photoresponse is attributed to trapping of photogenerated carriers in the GaAs buffer layer, causing a change in the potential profile and a consequent reduction in the number of carriers in the 2-DEG (two-dimensional electron gas) channel.<>
Keywords :
III-V semiconductors; aluminium compounds; carrier density; gallium arsenide; high electron mobility transistors; phototransistors; 2-DEG; AlGaAs-GaAs; MODFETs; buffer layer; drain current; gate-to-source bias voltage; negative photoresponse; optical power; photogenerated carriers; potential profile; Electron optics; Electron traps; Epitaxial layers; Gallium arsenide; HEMTs; Lighting; MODFETs; Optical buffering; Optical modulation; Voltage;
Conference_Titel :
Microwave Symposium Digest, 1993., IEEE MTT-S International
Conference_Location :
Atlanta, GA, USA
Print_ISBN :
0-7803-1209-0
DOI :
10.1109/MWSYM.1993.276735
