Physical basis and characteristics of light emission from quantizedplanar Ge structures
Venkatasubramanian, R., Malta, D. P., Timmons, M. L., & Hutchby, J. A. (1991). Physical basis and characteristics of light emission from quantizedplanar Ge structures. In International Electron Devices Meeting, 1991. IEDM '91, Washington, DC, Technical Digest, pp. 429–432. Washington, DC: .
The characteristics of luminescence from quantized planar Ge structures are presented, showing stability with time, dependence on laser power excitation and temperature, and the presence of GaAs-Al0.8Ga0.2As overlayers. A single broad emission at 1.7 eV near 300 K is observed to become four distinct emissions at 2.16 eV, 2.01 eV, 1.696 eV, and 1.56 eV at 77 K. A model describing the basis of luminescence in small Ge structures is also presented. The increased probability for radiative recombination in the quantized structures is a result of states in the conduction band and valence band being closed in k-space than in bulk Ge. Thus, the luminescence at 1.7 eV in the quantized structures probably results from a one or two phonon-assisted process compared to a 4-5 phonon process in bulk Ge for photoluminescence at 0.7 eV