非桥氧空穴发光中心对铁钝化多孔硅光致发光的影响

摘要

Hydrothermal etching method was employed to prepare iron-passivated porous silicon ( IP-Si) samples with peak energy around 2. 0 eV and FWHM of 0. 40 eV. As the excitation wavelength increases from 240 to 440 nm, the peak energy of photoluminescence red-shifts first, and then blue-shifts before it reaches a constant energy. The changing curve demonstrates a spoon-like pattern. By analyzing the statistics results from 15 IP-Si samples, it is found that the turnover excitation wave-length corresponding to the peak energy is about 330 nm and the related photon energy is 3. 8 eV. The spoon-like relationship found between the peak energy and excitation wavelength is in good agreement with the photoluminescence behavior under the combined action of two types of non-bridg-ing oxygen hole center of≡Si—O↑and≡Si—O↑…H—O—Si≡.%采用水热腐蚀法制备了铁钝化多孔硅样品，样品光致发光谱的荧光峰位于2.0 eV附近，半峰宽约为0.40 eV。激发波长从240 nm增大到440 nm的过程中，荧光峰先红移再蓝移，最后基本稳定，变化曲线呈勺型。通过分析15片发光多孔硅样品的统计结果，发现荧光峰逆转所对应的激发波长位于330 nm附近，相应的激发光子能量约为3.8 eV。样品光致发光谱随激发波长的勺型变化过程与≡Si—O↑和≡Si—O↑…H—O—Si≡两类非桥氧空穴发光中心共同作用时的发光行为一致。