Temperature dependence of threshold current for 1.8 to 2.3 µm (AlGaIn)(AsSb)-based QW diode lasers

We report on the temperature dependence of threshold current for ridge waveguide. Ga(1-x)In(x)As(y)Sb(l-y)/Al(0.29)Ga(0.71)As(0.02)Sb(0.98) triple-QW diode lasers grown by MBE on GaSb. In and As contents in the QW were in the 0.16<=x<=0.30 and 0<=y<=0.15 range, respectively, resulting in different strain states, band gap energies and band offsets. Devices with lasing wavelengths extending from 1.8 to 2.3 µm at room-temperature were tested in cw mode. Characteristic temperatures for the threshold current ranged from T(0)=172 K at 1.94 µm to T(0)=93 K at 2.23 µm and T(0)=52 K at 2.34 µm for the 200 to 280 K temperature interval. The pronounced drop in T(0) is associated with a significant decrease in the valence band offset from 0.27 eV to 0.22 eV and 0.14 eV.