High‐speed GaAs p‐i‐n photodiodes grown on Si substrates by molecular beam epitaxy

We present results on high‐speed GaAs p‐i‐n photodiodes grown on Si substrates by molecular beam epitaxy. In addition to the dc operating characteristics, we also report the first impulse response and microwave frequency response measurements of GaAs‐on‐Si photodiodes. Results include an impulse response pulse width of 45 ps and a modulation corner frequency >4 GHz at a reverse bias of −3 V.