Resonant germanium nanoantenna photodetectors.
On-chip optical interconnection is considered as a substitute for conventional electrical interconnects as microelectronic circuitry continues to shrink in size. Central to this effort is the development of ultracompact, silicon-compatible, and functional optoelectronic devices. Photodetectors play a key role as interfaces between photonics and electronics but are plagued by a fundamental efficiency-speed trade-off. Moreover, engineering of desired wavelength and polarization sensitivities typically requires construction of space-consuming components. Here, we demonstrate how to overcome these limitations in a nanoscale metal-semiconductor-metal germanium photodetector for the optical communications band. The detector capitalizes on antenna effects to dramatically enhance the photoresponse (>25-fold) and to enable wavelength and polarization selectivity. The electrical design featuring asymmetric metallic contacts also enables ultralow dark currents (approximately 20 pA), low power consumption, and high-speed operation (>100 GHz). The presented high-performance photodetection scheme represents a significant step toward realizing integrated on-chip communication and manifests a new paradigm for developing miniaturized optoelectronics components.
Geballe Laboratory for Advanced Materials, Stanford University, California 94305, USA.
Linyou
L
Cao
Joon-Shik
JS
Park
Pengyu
P
Fan
Bruce
B
Clemens
Mark L
ML
Brongersma
D005857:Germanium / Q000737:chemistry*; D049329:Nanostructures / Q000737:chemistry*; D036103:Nanotechnology / Q000295:instrumentation*; D010783:Photometry / Q000295:instrumentation*; D012666:Semiconductors
D005857:Germanium