Oxide thickness dependence of photocurrent for theGeO2/Gefilm system

Thermally surface oxidized Ge films show the photoconduction for photons with the energy hv ≥ 2.5eV. It is an interface phenomenon and this energy coincides with the barrier height at theGeO2/Geinterface. In this work, it was shown there exists an oxide thickness d suitable for getting maximum photocurrentΔiand it is 10 nm for theGeO2/Gefilm system. Identical behaviors were also found on TeO2/Te films. Thed-dependenceof transmissivity spectrum was measured and its relation to the change in Δi with hv and d was discussed in comparison with the TeO2/Te film system.