Visible Blind 4H-SiC P -N UV Photodiode Obtained by Al Implantation

This paper reports the electrooptical characteristics of ultraviolet light-sensitive 4H-SiC p⁺-n junction photodiodes obtained by aluminium (Al) ion implantation on low-doped n-type epilayers. A low dark current density (<; 1 nA/cm² at -100 V) was measured on 1-mm² area devices up to 90 °C. A peak responsivity of 0.11 A/W at 280 nm corresponding to a quantum efficiency of about 50% and a visible blindness> 10³ were demonstrated. The absence of optically active defects and nitrogen donor-aluminum acceptor pair recombination centers was monitored by optical measurements in the visible range.