热氧化硫化锌薄膜制备高质量纳米ZnO薄膜的表征

IDENTIFICATION OF HIGH QUALITY NANOCRYSTALLINE ZnO THIN FILMS PREPARED BY THERMAL OXIDATION

本文报道了利用低压-金属有机化学气相沉积(LP-MOCVD)技术生长ZnS薄膜,然后,将ZnS薄膜在氧气中于不同温度下进行热氧化制备高质量的纳米ZnO薄膜.采用有效的手段对样品的质量表征:X-射线衍射(XRD)结果表明,纳米ZnO薄膜具有六角纤锌矿多晶结构.喇曼光谱观测到典型的多声子共振过程.在光致发光(PL)光谱中,自由激子(FE)和束缚激子(BE)发射都很明显.低温下,束缚激子(BE)复合发射占主要地位,而自由激子(FE)复合发射也容易观察到.这些结果都说明我们制备的样品是高质量的.

In this paper, we report photoluminescence (PL) from the high quality nanocrystalline ZnO thin films. The high quality nanocrystalline ZnO thin films are prepared by thermal oxidation of ZnS films deposited by low-pressure metalorganic chemical vapor deposition (LP-MOCVD) technique. X-ray diffraction (XRD) indicates the nanocrystalline ZnO thin films with a polycrystalline hexagonal wurtzite structure. The Raman spectrum shows a typical resonant multi-phonon process within the ZnO film. In photoluminescence, the appearances of BE and FE emissions are a sharp peak, respectively. At low temperatures, BE recombinations dominate the PL spectrum, while recombinations of free excitons can also be easily identified. These findings emphasized here indicate that our samples are of high quality.