Investigations on the Thermal Weight Loss and the Photoluminescence Mechanism of AAO Template

In order to deeply understand the influence of oxalic impurities on the optical properties of anodic aluminum oxide(AAO),AAOs prepared in oxalic acid solution were investigated by the temperature programmed desorption combined with mass spectrograph(TPD-MS),thermogravimetric analysis(TGA),differential thermal analysis(DTA) and photoluminescence(PL) techniques.The thermal weight loss of AAOs was monitored in the temperature range between room temperature(RT) and 1200℃ and analyzed quantitatively.The analysis results indicate that the desorption of H 2 O,CO and CO 2 molecules and the decomposition of oxalic acid impurity occur below 402.2℃,therein water desorption is the main reason for the weight loss.In the temperature range of 402.2 866.7℃,the incomplete decomposition of aluminum oxalate occurs and gives birth to CO and CO 2 with CO as the major component.The drastic decomposition of aluminum carbonate and oxalate take place in the temperature range of 866.7 1022.9℃,CO 2 is the main product.According to the TGA results and the molar ratios of CO in the desorption products,the content variation of oxalic impurities intermingled in bulk AAOs is obtained with the change of temperature.At last,the correlation of the optical property for AAOs with the concentration of oxalic impurities and oxygen vacancies(F +) is proposed.