Photodetector Developed with 1.5-µm Sensitivity

Silicon-based photodetectors may benefit high-speed optical communications technologies because of their potentially simple integration. But developing a cost-effective, efficient detector that obtains a photoresponse in the 1.3- to 1.55-µm wavelength range necessary for communications applications has been a challenge.

Using germanium quantum dots embedded in undoped silicon, researchers from the University of California in Los Angeles have developed a PIN photodetector that they believe may provide a solution. In the Feb. 18 issue of Applied Physics Letters, they reported that the detectors show a photoresponse between 1.3 and 1.52 µm with an external efficiency of 8 percent at 1.4 µm.