In materials without a center of symmetry, such as ferroelectric materials, photocurrent can be produced in a homogeneous medium under uniform illumination, which is called the ferroelectric photovoltaic effect (FPE). We have fabricated Pb(Zr_0.3Ti_0.7)O₃ (PZT) ferroelectric thin films with Pt and ITO electrodes on Pt/Ti/SiO₂/Si substrates by using a sol-gel technique and investigated the photocurrent behaviors. The photocurrent of the Pt/PZT/Pt capacitor, which depended on the direction of polarization, exhibited a symmetric behavior, but that of the ITO/PZT/Pt capacitor, which also depended on the direction of polarization, exhibited an asymmetric behavior. The effects of the difference between the top electrode materials on the photocurrent behaviers of the Pt/PZT/Pt and ITO/PZT/Pt capacitors are discussed.

Keywords: Ferroelectric, Photovoltaic, Photocurrent, Thin Film, PZT, Ferroelectric Photovoltaic

결정구조 상 대칭중심을 가지지 않는 강유전 물질에 빛이 입사되면 광전류가 발생되는데 이 현상을 강유전체 광기전력 효과 (ferroelectric photovoltaic effect, FPE)라 한다. 졸-겔 방법으로 Pt/Ti/SiO₂/Si 기판 위에 Pb(Zr_0.3Ti_0.7)O₃ (PZT) 강유전체 박막을 제조 후 서로 다른 Pt와 ITO 상부전극을 사용하여 광전류 특성을 조사하였다. 분극 방향에 따른 Pt/PZT/Pt 캐패시터의 광전류는 대칭적이었으나 ITO/PZT/Pt 캐패시터의 광전류는 비대칭적이었다. 상부전극 물질 차이에 따른 Pt/PZT/Pt와 ITO/PZT/Pt 캐패시터의 광전류 특성 변화에 관하여 논의하였다.

Keywords: 강유전체, 광기전력 효과, 광전류, PZT, 박막, 강유전체 광기전력