Title :
Enhancement of quantum efficiency in thin photodiodes through absorptive resonance
Author :
Chin, Albert ; Chang, T.Y.
Author_Institution :
AT&T Bell Labs., Holmdel, NJ, USA
fDate :
3/1/1991 12:00:00 AM
Abstract :
The spectral response of resonantly enhanced photodiodes is analyzed theoretically and verified experimentally. Comprehensive design guidelines and formulas are given for device structures containing a metal reflector, a contact layer, and optional grading layer, an absorbing layer, and a quarter-wave stack (QWS). The analysis shows, for instance, that the quantum efficiency of a Schottky photodiode with a 162-nm GaInAs absorbing layer can be enhanced 3.7-fold by using a 41-layer AlInAs/AlGaInAs QWS. The number of layers required could be much lower for other material systems and/or if the substrate is removed. Experimentally, 50% enhancement is demonstrated for a 475-nm-thick absorbing layer at 1.52 μm by using a 16-layer QWS. The resonance width is ~4.4%
Keywords :
III-V semiconductors; Schottky-barrier diodes; gallium arsenide; indium compounds; light absorption; optical films; photodiodes; 1.52 micron; 475 nm; AlInAs-AlGaInAs; GaInAs; Schottky photodiode; absorbing layer; absorptive resonance; contact layer; design guidelines; device structures; layer number; metal reflector; optional grading layer; quantum efficiency; quarter-wave stack; resonance width; resonantly enhanced photodiodes; spectral response; thin photodiodes; Absorption; Bandwidth; Detectors; Equations; Guidelines; Optical sensors; Photodetectors; Photodiodes; Resonance; Ultrafast optics;
Journal_Title :
Lightwave Technology, Journal of
