Photoelectrochemical Characteristics for Cathodic Electrodeposited Cu2O Film on Indium Tin Oxide

Cuprous oxide (Cu$_2$O) thin films are cathodically deposited on Indium Tin Oxide (ITO) substrate. The as-deposited films were heat-treated at 30$0^{\circ}C$ to obtain Cu$_2$O. After the heat treatment, the film was changed from Cu metal into Cu$_2$O phase. The phase, morphology and photocurrent density of the films were dependent on the preparation conditions of deposition time, applied voltage, and the duration of heat treatment. The Cu$_2$O films were characterized by X-Ray Diffractometer (XRD) and Scanning Electron Microscope (SEM). The apparent grain size of the films formed by the normal method was larger than those grown by the pulse method. The CU$_2$O film what was deposited at -0.7 V for 300 sec and then, calcined at 30$0^{\circ}C$ for 1 h showed the predominant photocurrent density of 1048 $\mu$A/$\textrm{cm}^2$. And the stability of Cu$_2$O electrodes were improved with chemically deposited TiO$_2$ thin films on Cu$_2$O.

음극전착법을 이용한 Cu2O 막의 광전기 화학적 특성

음극전착법을 이용하여 전도성유리(ITO-glass)위에 Cu$_2$O 막을 제조하였다. Cu$_2$O 막의 특성을 향상시키기 위하여 전착방법, 시간, 전압, 전착 후 열처리 조건을 변화시켰다. 전착 후 열처리를 통해 얻어진 전극에 100mW/$ extrm{cm}^2$의 백색광을 조사하여 광전류밀도를 측정하고 XRD, SEM, UV-visible spectrophotometer를 통해 제조 조건변화에 따른 특성변화를 관찰하였다. 그리고 100mW/$\textrm{cm}^2$의 백색광하에서 bias 전압이 0V인 조건에서 전극의 안정성을 측정하였다 인가전압 -0.7V, 인가시간 300초 전착 조건에서 얻어진 막을 30$0^{\circ}C$에서 1시간 열처리하여 순수한 Cu$_2$O 막을 제조하였으며, 이 전극을 이용 광전류밀도를 측정한 결과 1048 $\mu$A/$\textrm{cm}^2$가 측정되었다. 또한 chemical deposition을 이용 TiO$_2$ 박막을 Cu$_2$O 막 위에 코팅하여 전극의 안정성을 향상시켰다.