Carrier Activation of Sol-gel Derived ZnO:Al Films Using Infrared Heating Method

探討以紅外線加熱溶膠凝膠法製作摻雜鋁氧化鋅薄膜載子之活化效應

本研究探討紅外線加熱溶膠凝膠法對摻雜鋁氧化鋅薄膜光電與化學性質的影響，文中並討論鋁和鎂的摻雜量對於載子的活化效果。實驗顯示，如同摻雜鎵氧化鋅薄膜一般，紅外線加熱法可有效改變摻雜鋁氧化鋅薄膜的孕核行為，並明顯提高摻雜鋁氧化鋅薄膜的導電性。而高活性的鎂離子除可改變溶膠錯合物的結構外，並能改變氧化鋅孕核行為以及載子活化效率。由於添加鎂可降低溶膠內醋酸鋅單體的沉澱速率，因此能稍提高摻雜鋁氧化鋅薄膜的載子濃度。但過量的鎂含量會阻礙載子的運動，並降低載子遷移率，導致薄膜導電率變差。

The purpose of this paper is to examine how Infrared heating procedure affects the opto-electrical and chemical properties of ZnO:Al (AZO) films and to investigate the influences of Al and Mg elements on the dopant activation of AZO films prepared by sol-gel method. In our experiments, the infrared heating method effectively enhanced the activation effects of Al dopant and thus improved the conductivity of AZO films. Moreover, the electropositive Mg was successfully used to modify the complex structure in the sol solution and to affect the nucleation as well as the carrier activation behaviors of the AZO films. Experimental results show that adding Mg could slightly increase the carrier concentration because it productively constrained the precipitation of zinc monoacetate in the sol-solution and retarded the oxidation of Al during the film growth process. Yet too much Mg lowered the carrier mobility, and the conductivity was thus reduced.