Cu2O-Ag奈米複合薄膜之光學性質和光電行為的研究

Study of the Cu2O-Ag Nanocomposite Thin Films on Optical and Photoelectrical Behaviors

曾建誌(C. C. Tseng) ； 謝章興(J. H. Hsieh) ； 張佑任(Y. J. Chang) ； 吳威德(W. Wu)

《真空科技》 26卷1期 (2013/03) Pp. 45-49

摘要

Cu2O-Ag薄膜利用反應式濺鍍沉積於玻璃和ITO基板上；沉積期間，改變Ag含量與沉積溫度；沉積之後，薄膜微結構使用X光繞射儀器（XRD）與穿透式電子顯微儀（TEM）來分析。而紫外－可見光光譜儀和光電化學量測系統可用來觀察到薄膜的光學與電性特性。由XRD和TEM研究Cu2O-Ag奈米複合薄膜得知，會有Cu2O，Ag2O和少部分Ag相共存於薄膜內部；從紫外－可見光光譜儀結果發現隨著銀含量增加，其光吸收隨之增加；另一方面，由光電化學量測結果顯示，銀含量於4 at.%時，有最顯著的光激發電流的效應，此意味著是Ag2O和Cu2O結合會增加光吸收和產生較多的電子電洞對，這是因為低能階的Ag2O所導致，而Cu2O-Ag2O的影響會增加電子電洞對的產生並改善光激發電流的效率。關於Ag2O對光電流與量子效率（IPCE）的影響將詳細討論。

關鍵字

Cu2O-Ag奈米複合薄膜 ； 量子效率

並列摘要

Cu2O-Ag thin films were co-deposited by reactive sputtering on glass and ITO substrates. During deposition, Ag contents and deposited temperatures were varied. After deposition, the microstructure of the films was examined using X-ray diffractometry (XRD) and transmission electron microscopy (TEM). A UV-VIS-NIR photometer and a photoelectrochemistry measurement system were used to characterize the optical and electrical properties of these films. The XRD and TEM study reveals that Cu2O-Ag nanocomposite consists of Cu2O, Ag2O, and small amount of Ag phases.The results showed that the Cu2O-Ag thin films had a decreased optical transmittance with the increase of Ag contents, while the absorptance was increased. On the other hand, the photo-current obtained from photoelectrochemistry measurement revealed that the sample with 4.0 at.% Ag showed the most significant response. The coupling of Ag2O phase with Cu2O can enhance light absorption and create more electron-hole pairs due to the small band gap of Ag2O. This coupling can enhance electron-hole separation and improve the efficiency of photon-induced current. The effects of Ag2O phase on photocurrent and quantum efficiency (IPCE) are discussed.

並列關鍵字

Co-deposited ； Ag Contents ； Deposited Temperatures ； Optical ； Photoelectrochemistry