Ga0.47In0.53As ultrahigh gain, high sensitivity photoconductors grown by chloride vapor-phase epitaxy

We report highly sensitive planar, interdigitated Ga0.47In0.54As photoconductive detectors prepared by trichloride vapor-phase epitaxy. The devices exhibit dc gains as high as 104 at 1.3 μm. For a bit rate of 500 Mbit/s a sensitivity of P̄=−35.4 dBm has been measured at 1.55 μm. With devices having unity gain quantum efficiencies of η=33% we obtain ηP̄=−40 dBm matching the highest sensitivity measured with a p-i-n photodetector at similar bit rates. The devices show responsivities in excess of 3000 A/W and detectivities ranging between 1012 and 1013 cm Hz1/2 W−1. These values represent the highest performance that has ever been achieved with photoconductors in this wavelength range.