  We report superfluorescent (SF) emission in electrically pumped InGaN/InGaN
QW lasers with saturable absorber. In particular, we observe a superlinear
growth of the peak power of SF pulses with increasing amplitude of injected
current pulses and attribute it to cooperative pairing of electron-hole (e-h)
radiative recombinations. The phase transitions from amplified spontaneous
emission to superfluorescence and then to lasing regime is confirmed by
observing (i) abrupt peak power growth accompanied by spectral broadening, (ii)
spectral shape with hyperbolic secant envelope and (iii) red shift of central
wavelength of SF emission pulse. The observed red shift of SF emission is shown
to be caused by the pairing of e-h pairs in an indirect cooperative
X-transition.
