High-performance p-i-n Ge on Si photodetectors for the nearinfrared: from model to demonstration

We have investigated the integration of Ge p-i-n and n-i-p heterojunction photodiodes on Si. Recognizing the crucial role of interface defects at the Ge-Si interface on the performance of photodetectors, we have designed and fabricated high-performance n-i-p Ge photodiodes on p⁺-Si substrates. These photodiodes exhibit short-circuit responsivities of 0.3 and 0.2 A/W at 1.3 and 1.55 μm, respectively, reverse dark currents of 20 mA/cm² and response times of 800 ps