ZnO纳米晶/巯基乙酸复合膜的荧光特性

用自组装方法将巯基乙酸(MPA)与ZnO纳米晶薄膜(ZDF)通过共价键偶联到一起，形成纳米晶／巯基乙酸复合膜(ZDF／MPA)。采用发光光谱和XPS电子能谱技术，研究了ZDF／MPA的荧光特性以及它们之间的能量传递机制。研究发现ZDF／MPA中ZnO自由激子发光和束缚激子发光强度随着巯基乙酸的浓度增大而分别呈现不同的非线性减弱关系，当巯基乙酸达到一定的浓度量时，ZnO荧光完全消失。研究表明：ZnO纳米薄膜与MPA之间能够发生成键作用，并且在成键之后发生了能量传递。

Effect of Mercaptoacetic Acids on Photoluminescence of ZnO Nanocrystals Thin Film

Complex films of mercapacetic acetic (MPA) and ZnO were formed by adding ZnO nanocrystals film on Si substrate to the chloroform solution of mercaptoacetic acetic. The (Zn)(S) bond was formed, which may be demonstrated by XPS. The fluorescence properties of ZnO thin film has been influenced by the amount of coated mercaptoacetic acids. With increasing the amount of mercaptoacetic acids, the ratio of coated surface increased. By characterization of photoluminescence, we found that the free exciton and bound exciton decreased. To those phenomena, we explained them by the electron transfer between ZnO and mercaptoacetic. Firstly, when bonds between ZnO and mercaptoacetic were formed, the electrons excited wouldn't combine with holes and the electrons would transfer into the level of mercaptoacetic acids. Thus, the ratio between electrons and holes of ZnO decreased and the intensity of its photoluminescence decreased. Secondly, the amount of mercaptoacetic acids would influence on the ratio of electrons and holes of ZnO. The mercaptoacetic acids increased, the ratio of electron transfer enhanced. So we may obtain the data of photoluminescence that the intensity of photoluminescence decreased with increasing the amount of mercaptoacetic acids. Otherwise, the profile photoluminescence of ZnO modified with mercaptoacetic acids showed that the intensity of ZnO photoluminescence decreased gradually with the distance of ZnO layer near to the surface.