大气中长期存放与长时间热氧化后多孔硅光致发光峰能量的会聚

PEAK ENERGY FOCUSING OF PHOTOLUMINESCENCE FROM POROUS SILICON DURING STORING IN AIR OR 200℃ THERMAL OXIDATION

改变阳极氧化的工艺条件,制备出光致发光峰能量位于1.4—2.0eV范围内的大量多孔硅样品,其中45块样品在大气中存放一年,102块样品在200℃下热氧化(累计达200小时).在上述两种情况下,光致发光峰能量在氧化后都会聚到1.70—1.75eV能量范围.假设在充分氧化的多孔硅中包裹纳米硅的氧化层中,存在发光能量处于～1.70—1.75eV的发光中心,上述实验结果可以用量子限制/发光中心模型解释.

Porous silicon (PS) samples with photoluminescence (PL) peak energies in the range of 1.4 to 2.0 eV were obtained by varing anodization conditions. 45 pieces of PS sample were stored in air for one year, and 102 pieces of PS sample were thermally oxidized at 200℃for 200 hours. After these two kinds of oxidation processes, PL peak energies of all PS samples focused to around 1.70-1.75eV. Supposing that luminescence centers with luminescence energies around 1.70-1.75eV exist in SiOx(x - 2) layers covering nanoscale silicon in fully oxidized PS, reported can be explained by the quantum confinement/luminescence centers model.