Blue-violet avalanche-photodiode (APD) and its ionization coefficients in II-VI wide bandgap compound grown by molecular beam epitaxy

We present II-VI wide bandgap semiconductor ZnSe and ZnSSe based blue-violet avalanche photo-diode (APD) operation grown on GaAs substrate by molecular beam epitaxy (MBE). Because of highly improved, crystal quality of the active layer, the ZnSSe APD reveals stable and high avalanche gain (G greater than or equal to 60) in the blue-violet optical region under high field operation condition (E = 1.15 x 10(6) V/cm) at room temperature (RT). High electric field induced ionization coefficients alpha (for electrons) and beta (for holes) are determined as a function of electric field strength E(V/cm); alpha(E) = 1.7 x 10(7) exp (-4.9 x 10(6)/E) and beta(E) = 3.7 x 10(6) exp (-4.0 x 10(6)/E).