退火温度对Al掺杂ZnO薄膜结构和光学性质的影响

Effect of annealing temperature on structure and optical properties of Al-doped ZnO film

采用溶胶-凝胶法在石英衬底上沉积Al掺杂的ZnO(AZO)纳米薄膜,研究了退火温度对薄膜的结构和光学性质的影响.结果表明:AZO薄膜呈c轴择优取向的纤锌矿结构.在一定的温度范围内,晶粒尺寸的大小随退火温度的升高而增加.当退火温度为900℃时,样品表面平整致密,样品可见光区的透射率达80%.当温度上升1 000℃时,晶粒尺寸达到最大,但样品表面出现裂纹,可见光区域的透射率下降.进一步提高退火温度则由于热缺陷导致了结晶质量的退化,一定范围内退火温度的升高能够提高样品的晶体中原子排列的有序性,有助于晶粒的长大,但同时也增加了样品内氧空位(Vo)和锌间隙(Zni)的缺陷浓度.

The Al doped ZnO （AZO） thin films were deposited on quartz substrates with sol gel method and the effect of annealing temperature on the structure and optical properties of the samples was investi gated. The result showed that the AZO film would exhibit a fibro zinc mineral structure with orientation priority to caxis. The grain size would increase with the annealing temperature in a certain range of tern perature. When the annealing temperature was 900℃, the sample surface would be smooth and compact and its visible light transmittance would amount to 80%. When the temperature was increased to 1 000 ℃ , the grain size would reach its maximum and tiny cracks would appear on the sample surface, degrading its visible light transmittance. Further elevation of annealing temperature over 1 000 ℃ would lead to deg radation of AZO crystal line quality due to thermal defect. Elevation of annealing temperature within cer tain range could improve the orderliness of atomic arrangement in the crystal line of the sample and would be contributive to grain growth. However, the high annealing temperature would also induce defect con centration to increase, such as oxygen vacancy defect （Vo） and interstitial zinc defect （Zni）.