GaNAs avalanche photodiode operating at 0.94 mu m

A p-i-n avalanche photodiode (APD) using GaNAs grown on GaAs has been demon strated. Characterization of the excess noise in the material was used to d etermine that the ratio of ionization coefficients (k=beta/alpha) is k=0.4. The quantum efficiency was above 25% at 0.94 mu m for 0.75% nitrogen incor poration. The APDs exhibited low dark currents (< 60 nA/mm(2) at 90% of bre akdown) and a gain-bandwidth product of 42 GHz. GaNAs therefore shows promi se for extending the operation of GaAs-based APDs to longer wavelengths. (C ) 2000 American Institute of Physics. [S0003-6951(00)03420-3].