Dark-current and capacitance analysis of InGaAs/InP photodiodes grown by metalorganic chemical vapor deposition

Electron traps have been observed at the InGaAs/InP heterointerface by capacitance voltage measurements in p-i-n photodiodes grown by metalorganic chemical vapor deposition. These traps might be responsible for the sharp increase in dark current which occurred when the space-charge region extended to the InP buffer layer. In addition, the temperature and voltage dependence of dark current has been described using a generation current model which takes into account the thermoionic field emission from an InGaAs midgap trap.