The characteristics of 3C-SiC pn structures created by sublimation epitaxy in vacuum on 6H-SiC (0001) substrates produced by Lely method are presented. In the structures selected for the study green injection electroluminescence (IEL) which is usually considered to be due to the free exciton annihilation was most uniform and intensive and the leakage current was lowest. The emission band in the green region of spectrum is dominant. The peak parameters at room temperature (RT) are the as follows: hv(max) approximate to 2.3 eV, full width at half maximum is about 90-100 meV. The behavior of the IEL intensity of the green peak as a function of the current is described by a power law, L similar to I-m there m=1.2, over broad range of the current. On heating the diode both the IEL intensity of the green peak at hv(max) and band width increase. At low current densities the dependence of the current on voltage is exponential: J = J(0) exp(qV/nkT) with the ideality factor nsimilar to3 at RT; with increasing temperature IN characteristics remain exponential, with a decreased ideality factor. The J-V characteristics are fairly close to those of high-perfection pn homostructures based on bulk 3C-SiC, with some indications of tunneling currents at low temperatures.