15:15 〜 15:30
▲ [13p-D305-6] Photoluminescence Recovery after its Quenching by Carrier Injection in Partially Oxidized Porous Silicon
キーワード:porous silicon, nanocrystalline, luminescence
We use a photoconduction technique to study the electrochemical oxidation (ECO) of p-type PSi and the phenomenon of photoluminescence (PL) quenching triggered by electron injection from the substrate. First we show quantum confinement effects during ECO and confirm that ECO proceeds by oxidizing selectively first large nanocrystallites and later on smaller ones. Second, PL recovery after stopping electron injection was studied for different oxide level, emission energy, electron injection levels and electric polarizations. The recovery time was quite short for non-oxidized PSi but became longer as the oxide level was increased, reaching minutes in some cases. The mechanism s will be discussed.