Dark current analysis and characterization ofInxGa1-xAs/InAsyP1-y gradedphotodiodes with x>0.53 for response to longer wavelengths(>1.7 μm)

The dark current properties of In_xGa_1-xAs photodiodes, where x is varied from 0.53 to 0.82 for extending the long wavelength cutoff from 1.7 to 2.6 μm, are described. Detailed analyses of optoelectrical parameters of In_0.82Ga _0.1As photodiodes are presented. Dark current, which is a critical parameter and limits the operation of the photodiode, is analyzed and compared with the experimental values. Typical characteristics of photodiodes with cutoff wavelengths of 1.7 μm (x=0.53), 2.2 μm (x=0.72), and 2.6 μm (x=0.82) are presented. The typical and best values of the dark currents obtained are presented