Micro Photo Detector Fabricated of Ferroelectric–Metal Heterostructure

• Published in: Japanese Journal of Applied Physics 2005-08, Vol.44 (8R), p.6105-6108
• Main Authors: Zomorrodian, A., Wu, N. J., Song, Y., Stahl, S., Ignatiev, A., Trexler, E. Brady, Garcia, C. A.
• Format: Article
• Language: English
• ISSN: 0021-4922; 1347-4065
• DOI: 10.1143/JJAP.44.6105

The anomalous photovoltaic effect (APE) in ferroelectric thin films has been utilized for the development of an optical micro-detector active in the visible range (from 350 to 800 nm). La-doped Pb(Zr,Ti)O 3 (PLZT) ferroelectric films epitaxially grown on Pt(001)/Mg(001) substrate were fabricated into micro-detector arrays and characterized as to their optical response. The Au/PLZT/Pt/MgO device was self-polarized in the as-deposited form with the polarization vector perpendicular to film surface. The heterostructure photovoltage response ranged from 100 to 200 mV, and the photocurrent was ∼ 30 nA/cm 2 for devices of ∼ 250 µm diameter under illumination of 100 mW/cm 2 at wavelengths from 400 to 580 nm. Such micro-detectors can be used for optical sensors in MEMS devices as well as for electrical stimulators of biological cells.