[23p-D316-1~17] 13.6 ナノ構造・量子現象・ナノ量子デバイス

▲ [23p-D316-15] Electron escape from porous silicon nanostructure probed by liquid-phase luminescence quenching dynamics

〇Bernard Gelloz¹、Lianhua Jin² (1.Nagoya Univ.、2.Univ. of Yamanashi)

キーワード：silicon, nanostructure, luminescence

The recovery of the photoluminescence (PL) of p-type porous silicon (PSi), after its quenching by electron injected from the substrate, was investigated. Electrons were injected into PSi by photo-generating electron-hole pairs in the substrate, which were then separated by applying an electric field, with electrons being forced into PSi. The PL was quenched as a result of an electron excess and fast Auger recombination. After electron injection was stopped, the PL recovered as electrons escaped from PSi back into the substrate by tunnelling through an energy barrier at the PSi/substrate interface. The energy barrier was tuned by growing an oxide in PSi using electrochemical oxidation. The higher the electron concentration in PSi, or the less transparent the energy barrier, the slower the PL recovery. The PL recovery was energy selective, the higher energy part of the spectrum recovering earlier than the lower energy part, in agreement with a band emptying itself from the top down. The effect of the quantity of electron injected into PSi was also studied and discussed.