In this work, suppression of the dark current level in a metal–semiconductor–metal (MSM) photodetector fabricated on the intrinsic (i) Ge is achieved by exploiting (1) the Er electrode, providing a relatively high hole barrier, and (2) the concept of asymmetric electrode area, to minimize the Schottky barrier height lowering effect. Compared with a symmetric MSM photodetector fabricated with Ti electrodes, the dark current level was reduced by a factor of about 80. This low dark current i-Ge MSM photodetector is promising for applications requiring low power and a high photo-to-dark-current ratio.
© 2011 Optical Society of America
Original Manuscript: January 4, 2011
Revised Manuscript: February 15, 2011
Manuscript Accepted: February 17, 2011
Published: March 25, 2011
Jin-Hong Park and Hyun-Yong Yu, "Dark current suppression in an erbium–germanium–erbium photodetector with an asymmetric electrode area," Opt. Lett. 36, 1182-1184 (2011)