Photoemission from cesium-oxide-activated InGaAsP

Abstract

Zinc-doped InGaAsP quaternary III-V material of the proper composition range shows superior photoemission properties to either InGaAs or InAsP ternary material. The minority-carrier diffusion length in the quaternary material is at least as long as that in InAsP and much longer than observed in InGaAs. The barrier height at the InGaAsP–Cs2O interface is lowered by cooling, giving increased electron escape probability and new highs in quantum efficiency over a wide wavelength range. For example, a 1.06-μ quantum efficiency of 7.5%/incident photon was observed at − 90 °C.