High-speed picosecond pulse response GaNAsSb p-i-n photodetectors grown by rf plasma-assisted nitrogen molecular beam epitaxy

The authors report on picosecond pulse response GaNAsSb/GaAs p-i-n photodetectors grown by molecular beam epitaxy in conjunction with a rf plasma-assisted nitrogen source. The 2 mu m thick GaNAsSb photoabsorption layer contains 3.3% of N and 8% of Sb resulting in a dc photoresponse up to 1380 nm wavelength. Dark current densities at 0 and -5 V are 1.6x10(-5) and 13 A/cm(2), respectively. The GaNAsSb photodiodes exhibit a record pulse response width of only 40.5 ps (full width at half maximum) corresponding to a 4.5 GHz bandwidth. (c) 2007 American Institute of Physics.