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