Electrical and optical characterization of GaSb based diode laser material for 2-4 mu m applications

摘要

Deep level transient spectroscopy, infrared absorption, or photoluminescence (PL) measurements were made on molecular beam epitaxially grown samples of Ga_(0.80)In_(0.20)As_(0.12)Sb_(0.88), AlAs_(0.07)Sb_(0.93), and InAs_(1-x)Sb_x (0.031 <=x<=0.192) ma6terials sued to develop 2-4 mu m quantum well laser structures lattice-matched to GaSb substrates. In addition to five other hole trap levels, a trap with the greatest effect on nonradiative recombination located at 276 meV above the valence band (E_v) was found in the Ga_(0.80)In_(0.20)As_(0.12)Sb_(0.ii active region material. A DX-like trap was found in the AlAs_(0.07)Sb_(0.93) cladding material at E_c-282 meV. Temperature-dependent absorption measurements made on undoped InAs_(1-x)Sb_x active region material resulted in the closed-form expression for the energy gap. The measured PL linewidth of the band-to-band transition of InAs_(1-x)Sb_x is narrower than any previously reported values, indicating the high quality of this material. Furthermore, two shallow impurity levels were resolved at energies 5-7 meV from the band edge.