Enhanced Room-Temperature 1.6 μm Electroluminescence from Si-Based Double-Heterostructure Light-Emitting Diodes Using Iron Disilicide

摘要

We have fabricated Si/β-FeSi_2/Si (SFS) double-heterostructure (DH) light-emitting diodes (LEDs) on Si(111) substrates with β-FeSi_2 thickness ranging from 80nm to 1μm, and Si_(0.7)Ge_(0.3)/β-FeSi_2/Si_(0.7)Ge_(0.3)(S_GFS_G) DH LEDs with a 200-nm-thick β-FeSi_2 layer using lattice-matched Si_(0.7)Ge_(0.3) layers by molecular-beam epitaxy. The electroluminescence (EL) peaked at an emission wavelength of approximately 1.6 μm at room temperature. As the thickness of the β-FeSi_2 layer was increased in the SFS DH LEDs, the emission power of EL increased for a given current density J. EL with an emission power of over 0.4 mW and an external quantum efficiency of approximately 0.1% was achieved for the SFS DH LED with a 1 -μm-thick β-FeSi_2 layer. The smallest J value necessary for EL output, which is approximately 1 A/cm~2, was achieved for the S_G FS_G DH LEDs.