Schottky barrier effects in the electronic conduction of sol–gel derived lead zirconate titanate thin film capacitors

Abstract

Pure and Fe-doped Pb(Zr0.53Ti0.47)O3 (PZT) thin film capacitors were fabricated by the sol–gel method and the leakage current versus voltage characteristics of these films were investigated at several temperatures and initial polarization states. After the initial poling of ferroelectric thin films, we measured two kinds of leakage current: (i) the full-switching current measured against an initial polarization direction and (ii) the nonswitching current measured toward an initial polarization direction. In the case of the full-switching current measurement, the anomaly of leakage current due to the switching of space charges was observed, which we suggest to be accumulated at a Schottky barrier region near an electrode or a gain boundary. In the case of the nonswitching current measurement, the Schottky diode rectifier current and the field-enhanced Schottky (ES) emission current came out without the switching current. The Poole–Frenkel emission process was dominant over ES emission for a Fe-doped PZT thin film having a large amount of space charge and traps. The height of the Schottky barrier in a Au/PZT film/Pt capacitor was measured to be 0.64 eV.

Effect of vanadium doping on ferroelectric and electrical properties of Bi3.25La0.75Ti3O12 thin film

“…Compared with previous results, it is reported the Schottky barrier height of SBT/SBN thin films in the range of about 1 eV [15,21]. The barrier height [24][25][26] of Ba 0.4 Sr 0.6 TiO 3 , Ta 2 O 5 and PZT thin films is 0.46 eV, 0.36 eV and about 0.6 eV, respectively. The Schottky barrier height of B = 0.2 eV for BLTV thin films is lower than that of other results.…”

Metal-ferroelectric-metal heterostructures with Schottky contacts. I. Influence of the ferroelectric properties

“…Screening the vast literature on this topic [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] the transport mechanisms can be grouped in two major categories: i) interface controlled mechanisms based on Schottky emission or Fowler-Nordheim tunneling and ii) bulk controlled mechanisms such as ohmic, space charge limited currents, Pool-Frenkel emission, ionic conduction, or a combination of them. However, the main dilemma arises from the question whatever the ferroelectric film should be treated as an insulator or as a semiconductor.…”

Electric characteristics of organic thin-film transistors and logic circuits with a ferroelectric gate insulator

“…The SiO 2 /Si substrate was a heavily n-type doped and thermally oxidized silicon wafer. The ferroelectric PZT thin films were prepared on Pt/Ti/TiO 2 /SiO 2 /Si substrates by a sol-gel technique [8]. Pentacene materials were purified using the vacuum sublimator at 10 − 3 Torr or lower.…”