High responsivity GaNAsSb p-i-n photodetectors at 13µm grown by radio-frequency nitrogen plasma-assisted molecular beam epitaxy

Abstract

GaNAsSb/GaAs p-i-n photodetectors with an intrinsic GaNAsSb photoabsorption layer grown at 350°C, 400°C, 440°C and 480°C, have been prepared using radio-frequency nitrogen plasma-assisted molecular beam epitaxy in conjunction with a valved antimony cracker source. The iGaNAsSb photoabsorption layer contains 3.3% of nitrogen and 8% of antimony, resulting in DC photo-response up to wavelengths of 1350nm. The device with i-GaNAsSb layer grown at 350°C exhibits extremely high photoresponsivity of 12A/W at 1.3μm. These photodetectors show characteristics which strongly suggest the presence of carrier avalanche process at reverse bias less than 5V. ©2008 Optical Society of America.