To overcome hole-injection limitation of p+-n emitter junction in 4H-SiC light triggered thyristor,a novel highvoltage 4H-SiC light triggered thyristor with double-deck thin n-base structure is proposed and demonstrated by twodimensional numerical simulations.In this new structure,the conventional thin n-base is split to double-deck.The holeinjection of p+-n emitter junction is modulated by modulating the doping concentration and thickness of upper-deck thin nbase.With double-deck thin n-base,the current gain coefficient of the top pnp transistor in 4H-SiC light triggered thyristor is enhanced.As a result,the triggering light intensity and the tu-on delay time of 4H-SiC light triggered thyristor are both reduced.The simulation results show that the proposed 10-kV 4H-SiC light triggered thyristor is able to be triggered on by 500-mW/cm2 ultraviolet light pulse.Meanwhile,the tu-on delay time of the proposed thyristor is reduced to 337 ns.