  We report Auger recombination rates for wurtzite InGaN calculated from first
principles density-functional and many-body-perturbation theory. Two different
mechanisms are examined -- inter- and intra-band recombination -- that affect
different parts of the emission spectrum. In the blue to green spectral region
and at room temperature the Auger coefficient can be as large as
2x10^-30cm^6s^-1; in the infrared even larger. Since Auger recombination scales
with the cubic power of the free-carrier concentration it becomes an important
non-radiative loss mechanism at high current densities. Our results indicate
that Auger recombination may be responsible for the loss of quantum efficiency
that affects InGaN-based light emitters.
