溶胶-凝胶法制备MgxZn1-xO薄膜的结构及光学特性

用溶胶-凝胶法制备了一系列的Mg_xZn_1-xO(0≤x≤0.3)薄膜,并用X射线衍射(XRD)和光致发光(PL)研究了不同的退火温度和Mg的掺杂含量对Mg_xZn_1-xO薄膜的结构和光学性质的影响.研究表明:Mg_xZn_1-xO薄膜为单相六角纤锌矿结构,并且具有沿c轴的择优取向;发现了中间热处理温度为350℃的Mg_xZn_1-xO薄膜退火温度的转折点为700℃,低于这个温度时随退火温度的升高,(002)衍射峰强度增强且掺Mg的薄膜既有紫外光又有绿光发射;800℃退火时,薄膜的(002)衍射峰强度减小,出现了(100)和(101)衍射峰,且掺Mg的薄膜只有紫外发光峰.不同的掺杂浓度对于发光也有影响,低于700℃退火时,ZnO薄膜只出现紫外发光峰,掺Mg的薄膜却出现了紫外和绿光两个发光峰.

Structural and Optical Properties of MgxZn1-xO Thin Films Prepared by Sol-gel Method

A series of Mg_xZn_1-xO(0≤x≤0.3)thin films were successfully fabricated by sol-gel method.The structural and optical properties were studied using XRD and photoluminescence spectrum.The results indicate that the Mg_xZn_1-xO thin films have hexagonal wurtzite single phase structure and a preferred orientation with the c axis perpendicular to the substrate.It was observed that there is an critical annealing temperature(700℃)of the Mg_xZn_1-xO(0.1≤x≤0.3)thin films preheating at 350℃,when annealing below this temperature,the intensity of(002)XRD peak increased,and the PL spectra of Mg_xZn_1-xO(0.1≤x≤0.3)thin films show both UV emission and green emission;when annealing above this temperature,the intensity of(002)peak decreased while(100)and(101)peak appeared,and the PL spectra of Mg_xZn_1-xO(0.1≤x≤0.3)thin films show only UV emission.The impurity concentration also affect the emission,when annealing below 700℃,the PL spectra of pure ZnO thin films show only UV emission,while the PL spectra of the Mg_xZn_1-xO(0.1≤x≤0.3)thin films show both UV emission and green emission.