A high-power low-loss fast and soft recovery p+(SiGeC)-n--n+ heterojunction diode is presented to meet the need of higher frequency in power electron circuits. Compared with conventional Si p-i-n diodes, the forward voltage drop of p+ (SiGeC)-n--n+ diodes is reduced by 20% when the operating current density does not exceed 1000 A/cm2, which effectively reduces the operating loss. The reverse recovery characteristics of the novel SiGeC diodes are much improved. The reverse recovery time is more than half shorter, the peak reverse current is 25% lower and the softness factor is increased 1.3 times. Furthermore, the leakage current and reverse block voltage are almost unchanged. Ge and C content is the important parameters to affect the characteristics of p+ (SiGeC)-n--n+, which offers more freedom to device design.