In this paper, the electrophysical characteristics of the 4H-SiC p-n junction created by low-temperature diffusion of aluminum were studied. Current-voltage (I-V) characteristics are analysed, and the current transport mechanisms in 4H-SiC p-n junctions are discussed. It is shown that at low forward bias voltages, the generation–recombination mechanism dominates, and the I-V characteristics at voltages U > 3.0 V obey the linear law. At reverse biases, the dominant mechanism of current transfer is limited by the space charge.