Analysis of different forward current–voltage behaviours of Al implanted 4H-SiC vertical p–i–n diodes

•The J–V characteristics of well behaved and leaky diodes in 4H-SiC are presented.•Almost all the diodes show good rectifying behaviours.•Experimental and simulation results are combined to extract key physical parameters.•The role of the diode internal resistance in determining a crossing point is discussed.•The simulated J–V characteristics are in good agreement with the experimental data.