Novel narrow band-gap InAsSbP-based quantum dot mid-infrared photodetectors: fabrication, optoelectronic and...

The InAsSbP quantum dots were grown on InAs(100) substrate by modified version of liquid phase epitaxy. The morphology, dimensions and distribution density of the quantum dots were investigated by an atomic force microscope. Two mid-infrared photodetectors made of InAs(100) substrate with and without InAsSbP quantum dots are fabricated and investigated. Current-voltage characteristics are measured and a deviation from linearity is detected for the quantum dot photodetector. Room temperature photoresponse spectra at low applied voltages are investigated. An anomalous photovoltaic effect is detected. Open circuit voltage and short circuit current generated in the quantum dot photodetector under irradiation of He-Ne laser operating at 3.39 microm are measured. Our measurements showed that voltage and current responsivities at room temperature are equal to 2 V/W and 82 mA/W, respectively. Specific dips in the quantum dot photodetector's room temperature capacitance-voltage characteristics are observed. Magnetic field up to 1.6 T was applied to measure the magnetoresistance at room temperature. Specific oscillations on magnetoresistance curve for the quantum dot photodetector are observed.