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用电化学阳极氧化法制备了不同孔隙率的多孔硅(PS)样品,然后用脉冲激光沉积(PLD)法在其表面生长ZnS薄膜,研究ZnS/PS复合体系的结构和发光特性。X射线衍射仪(XRD)结果表明,ZnS薄膜的生长具有高度择优取向,在28.5°附近有一很强的衍射峰,对应于β-ZnS(111)晶向。扫描电子显微镜像(SEM)显示,ZnS薄膜表面很不平整并出现空洞,这是由于衬底PS的表面粗糙所致。ZnS/PS复合体系的光致发光(PL)谱的高斯拟合分峰表明,随着衬底孔隙率的增大,在样品B和C的发光谱中,在光谱中间520nm左右都出现了一个新的绿色发光峰,归因于ZnS的缺陷中心发光。位于480nm附近的ZnS的蓝光和520nm附近的ZnS的绿光以及位于600nm处的PS的橙红光叠加在一起,整个ZnS/PS复合体系呈现出较强的白光。
Porous silicon (PS) samples with different porosity were prepared by electrochemical anodic oxidation. The ZnS thin films were grown on the surface by pulsed laser deposition (PLD) to study the structure and luminescence properties of ZnS / PS composite. X-ray diffraction (XRD) results show that the growth of ZnS thin film has a highly preferred orientation, a strong diffraction peak near 28.5 °, corresponding to the β-ZnS (111) crystal orientation. Scanning electron microscopy (SEM) shows that the surface of the ZnS thin film is very uneven and cavitates due to the surface roughness of the substrate PS. The Gaussian fitting peaks of the PL spectra of the ZnS / PS composites show that with the increase of the substrate porosity, in the emission spectra of the samples B and C, one appears at about 520 nm in the middle of the spectrum The new green luminescence peak is due to the defect center of ZnS emitting light. The blue light of ZnS near 480 nm and the green light of ZnS near 520 nm and the orange-red light of PS at 600 nm are superposed together, and the whole ZnS / PS composite system shows strong white light.