Open AccessPhoto-conductivity decay properties of Fe-doped congruent lithium niobate crystals
Author(s) -
Xiaolan Chen,
Yun Zhang,
Ran Qi-Yi
Publication year - 2013
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.62.037201
Subject(s) - lithium niobate , materials science , conductivity , polaron , exponential decay , doping , electron , potassium niobate , saturation (graph theory) , crystal (programming language) , analytical chemistry (journal) , ion , lithium (medication) , electrical resistivity and conductivity , laser , atomic physics , optics , physics , chemistry , optoelectronics , ferroelectricity , mathematics , chromatography , quantum mechanics , combinatorics , computer science , nuclear physics , dielectric , programming language , medicine , endocrinology
Photo-conductivity transient processes of Fe:LiNbO3 congruent crystals are investigated by electro-chemical analyzer. The experiments are executed with Fe:LiNbO3 crystals of different Fe concentrations in the conditions of different laser intensities. The results show that the transient photo-conductivity of the Fe-doped lithium niobate crystal is formed through a complex process of electron transport; the decay of photo-conductivity can be fitted to an exponential function and a stretched-exponential function. The dependences of the fitting parameters on laser intensity and iron-doped concentration are measured. The values of amplitudes σ1max, σ2max, time constant τ2 and stretching factor β increase strongly at low intensities, and τ2 and β reach their saturation value for higher intensities; with the increase of the concentration of Fe ions, the values of σ1max, σ2max and τ2 incerease, but β decreases. With experimental results, we propose a charge transfer model which includes the migration of electrons in the conduction band and the jumping of electrons between small-polarons. The model better explains the main features of photo-conductivity decay for Fe-doped congruent lithium niobate crystals.