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Ferroelectric Photocurrent Effect in Polycrystalline Lead‐Free ( K 0.5 Na 0.5 )( Mn 0.005 Nb 0.995 ) O 3 Thin Film
Author(s) -
Park Jungmin,
Won Sung Sik,
Ahn Chang Won,
Kim Ill Won
Publication year - 2013
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1551-2916.2012.05430.x
Subject(s) - poling , photocurrent , materials science , indium tin oxide , electrode , analytical chemistry (journal) , crystallite , photoconductivity , polarization (electrochemistry) , thin film , ferroelectricity , optoelectronics , chemistry , nanotechnology , chromatography , dielectric , metallurgy
We deposited ( K 0.5 Na 0.5 )( Mn 0.005 Nb 0.995 ) O 3 ( KNMN ) thin films on Pt(111)/ TiO 2 / SiO 2 / Si (100) substrates with a top electrode of indium tin oxide and investigated photocurrent properties in the wavelength range of 300−400 nm. Before the photocurrent measurement, the KNMN film was poled by applying a DC voltage. The photocurrents strongly depend on the wavelength of the incident photon energy. The photocurrents of the first measurement with poling in the up (−5 V) and down (+5 V) states were 21 and 3.2 nA/cm 2 , respectively, at 344 nm. The difference in the photocurrents in both poling directions was explained by a space charge due to an asymmetric Schottky barrier height, which was caused by an internal electric field and polarization in the KNMN thin film.