Analysis of the gain and luminescence properties of Si/Si1−xGx: Er/Si heterostructures produced by sublimation molecular-beam epitaxy in a gas phase

Si/Si1−xGex: Er/Si structures grown by sublimation molecular-beam epitaxy (SMBE) in a gas phase are studied. These structures are considered possible structures for realizing a Si/Er-based laser. It is shown that SMBE in a gas phase can be applied to create effective light-emitting structures that generate an intense luminescence signal at a wavelength of 1.54 μm. The structures and chemical compositions of the Si/Si1−xGx: Er/Si structures, whose parameters are close to those calculated for creating laser-type structures, are examined, and their photoluminescence (PL) spectra and kinetics are studied at 4.2 and 77 K. It is shown that the fraction of Er3+ optically active centers in the Si1−xGx: Er layers thus grown reaches ∼10% of the total erbium-impurity concentration. The optical gains in the active Si1−xGx: Er layers at x = 0.1 and 0.02 are estimated to be ∼0.03 and ∼0.2 cm−1, respectively. The gain in structures of this type can be significantly increased via the intentional formation of isolated Er3+ optically active centers whose PL spectra have a characteristic fine structure.