High Power, Room Temperature Terahertz Emitters Based on Dopant Transitions in 6H-Silicon Carbide

Electrically pumped high power terahertz(THz) emitters that operated above room temperature in a pulse mode were fabricated from nitrogen-doped n-type 6H-SiC. The emission spectra had peaks centered on 5 THz and 12 THz(20 meV and 50 meV) that were attributed to radiative transitions of excitons bound to nitrogen donor impurities. Due to the relatively deep binding energies of the nitrogen donors, above 100 meV, and the high thermal conductivity of the SiC substrates, the THz output power and operating temperature were significantly higher than previous dopant based emitters.With peak applied currents of a few amperes, and a top surface area of 1 mm2, the device emitted up to 0.5 mW at liquid nitrogen temperature(77 K), and tens of microwatts up to 333 K. This result is the highest temperature of THz emission reported from impuritybased emitters.