Enhanced thermoelectric properties of lightly Nb doped SrTiO₃ thin films

Abstract

Pulsed laser deposited Nb-doped SrTiO3 thin films with enhanced figure of merit (ZT = 0.5, at room T), can be a good alternate for n type thermoelectric oxide material.

Effect of Crystal Orientation on Seebeck Coefficient and Electrical Conductivity of SrTiO3 Single Crystals

“…The PF of sample Sto-C [270] is 2.3 mW m –1 K –2 at 323 K, close to that of sample Sto:La 2 mol %-C [160]. Sample Sto:La 2 mol %-C [270] has the highest PF value of 2.5 mW m –1 K –2 at 323 K. Its PF is higher than that of many SrTiO 3 ceramics. , The SrTiO 3 films are normally produced along the [100] or [110] direction. − Based on our experimental results of the single crystals, higher TE properties should be achieved along the [270] direction of the films. The optimization of the crystal orientation provides an efficient way to improve the TE properties.…”

“…Although the perovskite SrTiO 3 crystal is isotropic in a , b , and c directions, the difference in the atomic arrangement in other directions will make the SrTiO 3 crystal anisotropic in TE properties, which has not been well investigated until now. Research work on the TE properties of SrTiO 3 single crystals or films is mainly in two common directions, i.e., the [100] and [110]. − The investigation of anisotropy of TE properties in other crystal orientations should be essential to obtain high TE properties and provides practical guidance for the design and preparation of anisotropic SrTiO 3 materials, especially the SrTiO 3 films and textured ceramics. Thus, optimization of the TE properties of SrTiO 3 by anisotropic design has potential application in TE devices, such as TE power generators.…”

Multidimensionality of the Contact Potential Difference at the Nanoscale in Inorganic Oxides

“…Successive XRD measurements were performed while keeping the sample and the beam at the same spatial position. The 2θ angle was scanned from 10 to 120° to cover a wide enough range of structural information on SrTiO 3 . − As Figure S1 illustrates, our XRD measurements clearly show the absence of any phase transformation between 25 and 85 °C. Our result is in good agreement with the existing literature, as structural and phase transformations of SrTiO 3 are not encountered in the utilized range of temperatures, i.e., for temperatures between 25 to 85 °C. − …”

Manipulating the carrier concentration and phase transition via Nb content in SrTiO3

“…Doping is one of the easiest and most efficient ways to manipulate physical properties of STO, not only because of the change of the carriers, but also the structural change of the unit cell 19 – 21 . Doping of a small electrons may raise abundant interaction among charge, spin, orbital and lattice degree of freedom for SrTiO 3 , therefore display the intriguing physical properties such as rectifying behavior 22 , resistive switching phenomenon 4 , 9 , ionic polarization 23 , high permittivity with low dielectric loss 24 , 25 , thermoelectric 26 , 27 , inverse spin Hall effect 28 , luminescence 29 , quantum ferroelectric 30 and so on. Furthermore, many of these physical properties are believed to alter around the critical phase transition temperature (T AFD = 105 K, antiferrodistortive, abbrev.…”