Anomalously high thermoelectric power factor in epitaxial ScN thin films

Abstract

Thermoelectric properties of ScN thin films grown by reactive magnetron sputtering on Al2O3(0001) wafers are reported. X-ray diffraction and elastic recoil detection analyses show that the composition of the films is close to stoichiometry with trace amounts (similar to 1 at. % in total) of C, O, and F. We found that the ScN thin-film exhibits a rather low electrical resistivity of similar to 2.94 mu Omega m, while its Seebeck coefficient is approximately similar to-86 mu V/K at 800 K, yielding a power factor of similar to 2.5 x 10(-3) W/mK(2). This value is anomalously high for common transition-metal nitrides.Funding Agencies|Swedish Research Council (VR)|621-2009-5258

Microstructure and thermoelectric properties of CrN and CrN/Cr2N thin films

“…Nitride thin films (and other thermoelectric material) can be optimized by adding dopants, synthesizing semiconductor/metal multilayers and nanostructuring, leading to the simultaneous decrease of the electrical resistivity and the thermal conductivity [25,26] and resulting an improved thermoelectric performance (or figure-of-merit). The interest in using thermoelectrics based on early trans itionmetal nitrides is further underlined by the results on ScN-based materials, both pure ScN [27][28][29][30][31], ScN-based solid solutions and alloys [32][33][34], and superlattices [35][36][37].…”

Reduction of the thermal conductivity of the thermoelectric material ScN by Nb alloying

“…It possesses both a high carrier concentration (10 and has a low electrical resistivity of around 300 µΩcm. 1,11 Reported power factors for ScN are relatively high (2.5-3. 15 and molecular beam epitaxy (MBE).…”

“…[1][2][3][4][5][6][7][8] Scandium nitride (ScN) is one of them and is an n-type semiconductor with a reported indirect band gap of around 0.9 eV 9,10 . It possesses both a high carrier concentration (10 and has a low electrical resistivity of around 300 µΩcm.…”

Theoretical study of phase stability, crystal and electronic structure of MeMgN2 (Me = Ti, Zr, Hf) compounds

“…The Seebeck coefficient of ScN is relatively large (reaching -180 lV=K at 800 K) and because of its low electrical resistivity, large power factors between 2.5 and 3.5 9 10 -3 Wm À1 K À2 have been reported [9,10]. Doping and alloying ScN with heavy elements [11,12] and/or creating artificial layer interfaces such as metal/semiconductor superlattices [13][14][15][16] can alter properties and decrease the thermal conductivity, resulting in an enhanced zT.…”