Principles and Practices of Si Light Emitting Diodes using Dressed Photons
Motoichi Ohtsu, Tadashi Kawazoe
(Submitted on 23 May 2018, Uploaded on 28 May 2018)
keywords: dressed photon, silicon, phonon, annealing
This paper reviews basic research and technical developments on silicon (Si) light-emitting diodes (Si-LEDs) fabricated by using a novel dressed-photon–phonon (DPP) annealing method. These devices exhibit unique light emission spectral profiles in the wavelength range 900–2500 nm, including novel photon breeding features. The highest optical output power demonstrated was as high as 2.0 W. It is pointed out that boron (B) atoms, serving as p-type dopants, formed pairs whose length was three-times the lattice constant of the host Si crystal. These B atom pairs are the origin of the photon breeding. A phenomenological two-level two-state (TLTS) model is presented, revealing that the external electric and optical fields, applied during the DPP-assisted annealing, drastically decrease the height of the potential barrier between the two states. This decrease is the reason why the spatial distribution of B atoms is efficiently modified by the DPP-assisted annealing even at low temperature. The TLTS model and a stochastic model confirm that the optimum DPP-assisted annealing is realized by setting the ratio of the electron injection rate and the photon irradiation rate to 1:1. A phase diagram is presented as an aid for developing a novel theory for realizing more efficient and higher-power Si-LEDs.
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