Al掺杂原子分数及退火温度对ZnO薄膜光学特性的影响

Effects of annealing temperature and Al doping concentration on optical properties of ZnO thin films by sol-gel technique

采用溶胶凝胶法在（0001）Al2O3衬底上制备了不同掺杂原子分数的ZnO：Al薄膜，在Ar气氛中进行了600950℃不同温度的退火处理，研究了掺杂原子分数和退火温度对薄膜光致发光、光吸收和透射的影响。结果显示，薄膜的紫外峰强度随掺杂原子分数和退火温度的提高而增强，与缺陷相关的绿光强度却随着掺杂原子分数和退火温度的提高而降低；薄膜光学带隙随掺杂原子分数的提高从3．21eV增大到3．25eV；光吸收在可见光区随着退火温度的升高而增大，在紫外区却随着退火温度的升高而减小，透射与吸收的变化规律相反；薄膜吸收边随退火温度的升高出现轻微的红移。

ZnO： Al thin films doped with different aluminum concentration are deposited on（0001） sapphire substrates by the sol-gel technique. Thermal annealing of ZnO thin films is carried out in argon atmosphere from 600 to 950℃. The effects of annealing temperature and dopant concentration on the optical properties of ZnO： Al thin films are investigated. Results show that the UV peak intensity is enhanced as increasing annealing temperature and dopant concentration while green emission related with deep level defects is decreased. The optical band gap increases from 3.21 eV to 3.25 eV as increasing dopant concentration from 0.01% up to 1%. The optical absorption in the visible region increases with increasing annealing temperature while decreases in the ultraviolet region. The optical transmittance has the reverse changing tendency compared with the optical absorption. Red shift of the optical absorption edge occurs with increasing annealing temperature.