Doping concentration dependence of radiance and optical modulation bandwidth in carbon-doped Ga_0.51In_0.49P/GaAs light-emitting diodes grown by gas source molecular beam epitaxy

Double-heterostructure light-emitting diodes (LEDs) consisting of an n-Ga0.51In0.49P emitter, a carbon-doped p-GaAs active layer, and a p-Al0.30Ga0.70As cladding layer have been grown by gas source molecular beam epitaxy with halomethane carbon doping sources. CCl4 and CHCl3 have been used to vary the active layer C doping level from 1018 to 1020 cm-3. Measurements of LED optical modulation bandwidth indicate that the bandwidth increases with C doping, attaining a record value of 1.6 GHz at 1020 cm-3 C concentration. The LED radiance is observed to decline significantly in the 1019-1020 cm-3 range.