Dark current analysis and characterization of In/sub x/Ga/sub 1-x/As/InAs/sub y/P/sub 1-y/ graded photodiodes with x<0.53 for response to longer wavelengths (<1.7 mu m)

The dark current properties of In/sub x/Ga/sub 1-x/As photodiodes, where x is varied from 0.53 to 0.82 for extending the long wavelength cutoff from 1.7 to 2.6 mu m, are described. Detailed analyses of optoelectrical parameters of In/sub 0.82/Ga/sub 0.1/As 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 mu m (x=0.53), 2.2 mu m (x=0.72), and 2.6 mu m (x=0.82) are presented. The typical and best values of the dark currents obtained are presented.< >