Analysis of thermoelectric properties of amorphous InGaZnO thin film by controlling carrier concentration

Abstract

We have investigated the thermoelectric properties of amorphous InGaZnO (a-IGZO) thin films optimized by adjusting the carrier concentration. The a-IGZO films were produced under various oxygen flow ratios. The Seebeck coefficient and the electrical conductivity were measured from 100 to 400 K. We found that the power factor (PF) at 300 K had a maximum value of 82 × 10−6 W/mK2, where the carrier density was 7.7 × 1019 cm−3. Moreover, the obtained data was analyzed by fitting the percolation model. Theoretical analysis revealed that the Fermi level was located approximately above the potential barrier when the PF became maximal. The thermoelectric properties were controlled by the relationship between the position of Fermi level and the height of potential energy barriers.

Enhanced Thermoelectric Transport and Stability in Atomic Layer Deposited-HfO2/ZnO and TiO2/ZnO-Sandwiched Multilayer Thin Films

“…Energy harvesting via the thermoelectric (TE) effect has recently gained attention for its directly reversible heat to electricity conversion [1][2][3][4][5]. Thermoelectric efficiency is described by a dimensionless figure of merit, following the equation: zT = σS 2 T/κ, where σ stands for electrical conductivity, S for Seebeck coefficient and κ for thermal conductivity [1].…”

“…Among potential thermoelectric materials, oxides are currently being intensively studied owing to their good chemical and thermal stability, low toxicity, high abundance and excellent transparency. Zinc oxide (ZnO) is one of the most studied n-type transparent semiconductor oxides, as its electronic properties can easily be tuned by controlling the defect densities [3][4][5][6][7][8][9]. ZnO thin films can be deposited by a wide variety of fabrication techniques, such as atomic layer deposition [10][11][12][13][14][15], pulsed laser deposition [16], sputtering [17] and solution-based processes [18][19].…”

Temperature independent Seebeck coefficient through quantum confinement modulation in amorphous Nb-O/Ni-Ta-O multilayers

“…These authors have argued that solids with the phonon mean free path larger than that of charge carriers exhibit an enhanced thermoelectric efficiency in energy generation, cooling, and sensing applications, which may be realized in amorphous compounds [15]. This was demonstrated for several amorphous systems, such as NbO 2 [16,17], ZnO [18], In-Ga-Zn-O [19], ZnSnO 3 [20], In 2 MgO 4 [21], Cu-Ge-Te [22], Zr-Ni-Sn [23], Ge-Au [24], Si-Au [24], and TiO 2 -PbO-V 2 O 5 [25]. Other related properties, such as electrochemical, may also be enhanced by forming amorphous solids instead of their crystalline counterparts, as reported for amorphous NbO x [26].…”

P‐15: Thermal Conductivity Measurement of Indium‐Gallium‐Zinc‐Oxide Thin Films Utilizing Three‐Omega Method

“…Therefore, IGZO is one of the promising materials for achieving advanced displays such as large-sized rollable or transparent displays. On the other hand, IGZO can be used as a thermoelectric material because it shows more competitive thermoelectric property than other thermoelectric oxide materials [9]. Large-area capabilities of IGZO TFT are also promising for photovoltaic systems due to its large area capabilities [10].…”