Tokyo Metropolitan University (formerly Wushu University of Technology) announced that it has produced silicon light-emitting elements using germanium (Ge) quantum dots, and confirmed the phenomenon of luminescence based on current excitation at room temperature. Since the use of compatible manufacturing processes in CMOS processes and the desire to achieve laser oscillations, the implementation of silicon photons is a step closer.
The development of this light-emitting element is the Silicon Nanoscience Research Center of the Tokyo Metropolitan University Research Institute. In the i-layer of the silicon-based pin structure element, germanium microparticles (quantum dots) having a diameter of several tens to 100 nm are embedded, and the particles "have an effect of increasing the recombination rate between electrons and holes" (silicon nanoscience) Director of the Research Center, Professor of the Tokyo Metropolitan University, Faculty of Engineering, Marunouchi). Maruyama said, "The quantum dots are formed by the MBE (molecular beam epitaxy) method at a temperature of about 400 Â° C, so the manufacturing process of the components is compatible with the CMOS process." The active layer portion of the element has a diameter of about 3 Î¼m.
It has been confirmed that the element can emit light having a wavelength of about 1.2 Î¼m by current injection at room temperature (300 K). The internal quantum efficiency of luminescence is 10-2. Maruquan said, "In addition to high quantum efficiency, the component is stable both thermodynamically and chemically. It is more advantageous than existing silicon-based luminescent components."
In addition, this element also tends to increase the injection current and the luminescence intensity greatly. Therefore, Maruyama said, "If a resonator structure is formed by photon crystallization, laser oscillation should occur. In the future, it is planned to change the luminescence wavelength to It can be used for communication in the 1.5Î¼m band. It will be developed as an optical switch after 2 to 3 years, and it will be put into practical use."
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