InP/In0.53Ga0.47As heterojunction phototransistors grown by chemical beam epitaxy

We describe InP/In
0.53
Ga
0.47
As heterojunction phototransistors (HPT's) grown by chemical beam epitaxy (CBE). These devices exhibit high gain ( > 150) at signal levels as low as - 50 dBm. Compared to earlier devices of this type, the gain is relatively independent of the optical signal level. This is due primarily to the improved quality of the emitter-base heterojunction interface which, for these HPT's, is characterized by an ideality factor of 1.14. At an incident power level of -21 dBm the bandwidth is 14 MHz and the gain-bandwidth product is 4.8 GHz.