The processes of erbium impurity excitation in Si/Si1-xGex:Er/Si heteroepitaxial structures

作者：Krasilnikova L V^*; Stepikhova M V; Antonov A V; Shengurov V G; Krasilnik Z F

来源：Optical Materials, 2013, 35(7): 1404-1409.

DOI：10.1016/j.optmat.2013.02.015

• Semiconductors
• Heterostructures
• Molecular beam epitaxy
• Photoluminescence spectroscopy

We report a study into the photoluminescence excitation spectra of Er3+ ions in Si/Si1-xGex:Er/Si heteroepitaxial structures containing 10-31% germanium. The structures of this type are of interest for a laser realization on Si basis. It is shown that a characteristic maximum in the 1040-1050 nm region that appears in these structures is related with the backscattering effects of radiation in the silicon substrate. The excitation efficiency of Er impurity in Si/Si1-xGex:Er/Si structures is investigated in conditions of band-to-band and sub-bandgap optical pumping with the photon energies smaller than the bandgap of a Si1-xGex solid solution. The effective excitation cross-section of erbium ions is shown to depend on the excitation mechanism, the excitation energy, and the parameters of Si/Si1-xGex:Er/Si layers. The values of the effective excitation cross-section of Er3+ ions in Si/Si1-xGex:Er/Si structures were found to vary from 4 x 10(-15) is to 0.5 x 10(-16) cm(2) at T = 77K. These values are comparable with the highest values obtained for the excitation cross-section of Er3+ ions in silicon and exceed by several orders of magnitude the effective cross-section of Er3+ ions under direct (intra-atomic) excitation.

• 出版日期2013-5