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White electroluminescence (EL) from ZnO/GaN structures fabricated by pulsed laser deposition of Zn:In onto GaN:Mg/GaN structures MOCVD-grown on Al2O3 substrates has been observed. The white light is produced by superposition of two strongest emission lines, narrow blue and broad yellow, peaked at 440 and 550 nm, respectively. The intensity ratio of different EL lines from ZnO/GaN/Al2O3 structures depends on the ZnO film quality and drive current. The white EL is due to the high density of structural defects at the n-ZnO/p-GaN interface. A band diagram of the n-ZnO/p-GaN/n-GaN is constructed and a qualitative explanation of the EL is given. Conditions of ZnO deposition strongly affects the properties of the recombination emission and predetermines the EL spectrum of the LED structure if it does not have high quantum efficiency (more than 1%) such as in commercial LEDs. [ABSTRACT FROM AUTHOR]

The possibility of fabricating a ferroelectric FET based on a Pb(ZrxTi1 – x)O3/SnO2(PZT/SnO2) heterostructure is investigated. Sb-doped epitaxial SnO2/Al2O3 thin film deposited by YAG laser ablation from a metal target is used as the FET channel. The highest obtained electron mobility in the channel is 25cm2/(Vs) at an electron density of 8×1019cm–3. The possibility of growing PZT film directly on SnO2 film using two different techniques, laser ablation and magnetron sputtering, is demonstrated. Both methods have been used in the fabrication of Au/PZT/SnO2 capacitor heterostructures, whose top Au electrode is 250×250μm2 in size. These cells demonstrate a capacitance of 1000 pF at a 10-V bias and remnant polarization up to 16μC/cm2. A Au/PZT/SnO2/Al2O3 transistor structure with 94% modulation of the channel current is fabricated. The difference in the channel current under the effect of positive and negative remnant polarization of the undergate ferroelectric is 37%. © 2005 Pleiades Publishing, Inc. [ABSTRACT FROM AUTHOR]

The possibility of fabrication of a transparent ferroelectric field effect transistor (FFET) with a high electron mobility channel was demonstrated. The highest obtained electron mobility in the channel SnO 2 /c-Al 2 O 3 is 25 cm 2 /V·s and SnO 2 /r-Al 2 O 3 is 40 cm 2 /V·s at the electron density of 10 19 –10 20 cm -3 . A transparent FFET structure Au/PZT/SnO 2 /Al 2 O 3 has been fabricated. The best sample had 94% conductivity modulation at the gate voltage from -5 V to 2 V. The difference in the channel current at positive and negative remnant polarizations of the undergate ferroelectric is 37%. [ABSTRACT FROM AUTHOR]