Namely, the band gap and n type {HEAD ~ doping} of the wide band gap layer are adjusted to suppress {TAIL ~ diffusion} of the thermally excited carriers 
are adjusted to suppress
Namely , the band gap and n type { HEAD ~ doping } of the wide band gap layer are adjusted to suppress { TAIL ~ diffusion } of the thermally excited carriers
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH REL REL REL REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH