Elemental

2) Compound Semiconductors
Group III-V : GaAs, GaP, InSb, InP, GaN
II-VI : HgTe, CdSe, ZnS, CdTe ...
‣ GaAs, InP 는 주로 MMIC나 LASER에 유용하다.
참고) ()
∙GaAs
∎ Gunn effect (negative resistance)
고전계를 가하면 ,
∴ 이므로 가 증가하고, 이 감소하여도 가 매우 작으므로 무시!
∙Gunn effect의 조건 :
i) mass of lower valley < mass of higher valley
mobility of lower valley > mobility of higher valley ()
ii) > energy difference between two conduction valley
otherwise, gunn effect 이전에 avalanche 발생
∎ Double barrier structure
∎ Esaki Diode
∙GaP
・direct conduction valley (2.88eV) → used as a LASER material combined with GaAs
・indirect conduction valley (2.1eV) → LED by N doping
* recombination center vs. trapping
:확률에 있어서 C・B로 다시 돌아갈 확률이 크면
trapping, V・…(생략)

② Energy gap linearly changed.

③ Inverse mass band parameters linearly changed.