Microwave modulation of exciton emission in molecular controlled semiconductor resistor

A GaAs/AlGaAs structure coated with molecules was investigated utilizing mi crowave modulated photoluminescence (MMPL) spectroscopy. This method enable d to resolve the photoluminescence (PL) band into localized and de-localize d excitons. The results indicated a limited in-plan mobility of the exciton s, due to electrostatic fluctuations or band bending induced by the adsorbe d molecules. The reduction of exciton mobility is correlated with the reduc tion in the photocurrent observed in former studies. The present study prov ides an insight into the mechanism which couples molecules with a semicondu ctor structure and explains its operation as a molecular controlled semicon ductor resistor (MOCSER), found to be a sensitive actuator in sensor applic ations. (C) 2001 American Institute of Physics.