Recombination and absorption measurements performed on double heterostructure films grown by metalorganic chemical vapor deposition are used to deduce B, the coefficient of radiative recombination for n-type GaAs with electron concentrations (n(0)) from 1.3 x 10(17) to 3.8 x 10(18) cm(-3). The radiative and non-radiative components of recombination were separated and the effects of photon recycling were taken into account. It is found that B = 3.5 x 10(-10) cm(3)/s for low n(0), and that B decreases significantly with increasing n(0) to as low as B = 1.8 x 10(-10) cm(3)/s for n(0) = 3.8 x 10(18) cm(-3). (C) 2009 Elsevier B.V. All rights reserved.