title: High-efficiency metal-semiconductor-metal photodetectors on heteroepitaxially grown Ge on Si.
abstract: We demonstrate extremely efficient germanium-on-silicon metal-semiconductor-metal photodetectors with responsivities (R) as high as 0.85 A/W at 1.55 microm and 2V reverse bias. Ge was directly grown on Si by using a novel heteroepitaxial growth technique, which uses multisteps of growth and hydrogen annealing to reduce surface roughness and threading dislocations that form due to the 4.2% lattice mismatch. Photodiodes on such layers exhibit reverse dark currents of 100 mA/cm2 and external quantum efficiency up to 68%. This technology is promising to realize monolithically integrated optoelectronics.
authors.affiliation: Center for Integrated Sysmstems, Stanford University, Stanford, California 94305, USA. aokyay@stanford.edu
authors.forename: Ali K
authors.initials: AK
authors.lastname: Okyay
authors.forename: Ammar M
authors.initials: AM
authors.lastname: Nayfeh
authors.forename: Krishna C
authors.initials: KC
authors.lastname: Saraswat
authors.forename: Takao
authors.initials: T
authors.lastname: Yonehara
authors.forename: Ann
authors.initials: A
authors.lastname: Marshall
authors.forename: Paul C
authors.initials: PC
authors.lastname: McIntyre