Analysis of temperature dependence of Ge-on-Si p-i-n photodetectors

M. Balbi, V. Sorianello, L. Colace and G. Assanto

Physica E 41, 1086-1089 (2009)


We investigate the temperature dependence of p-i-n photodetectors realized in germanium on silicon. The dark current increases by a factor 1.6-1.9 every 10C and is tipically dominated by generation in the space charge region, with diffusion contributing in the best samples. The near infrared (NIR) responsivity decreases with temperature in devices with a large defect-densities, but is more stable in high-quality photodiodes. These findings provide a relevant insight on the design of Ge-on-Si NIR detectors to be operated above room temperature.