The reverse and forward currents of Al+ ion implanted 4H-SiC p+-in diodes have been compared for identically processed devices except for the implanted Al concentration in the emitter, 6× 10 19 cm− 3 against 2× 10 20 cm− 3, and the post implantation annealing treatment, 1600 C/30 min and 1650 C/25 min against 1950 C/5min. The diodes' ambipolar carrier lifetime, as obtained by open circuit voltage decay measurements, has been compared too. The devices with lower annealing temperature show lower leakage ...