Improvement of Thermoelectric Properties of Evaporated ZnO:Al Films by CNT and Au Nanocomposites

Abstract

Nanocomposites are a popular choice to improve the thermoelectric (TE) performance of materials by breaking the tradeoff among the TE parameters. However, the generation of depletion layers at the nanocomposite interfaces limits the improvement of the TE performance. This study employs carbon nanotube (CNT) and Au nanocomposites to solve this problem in evaporated ZnO:Al films assisted by a radio frequency atomic source. The results show that the carrier concentration and mobility are tuned individually by the CNT and Au nanocomposites. The conductivity increases by increasing the carrier concentration and mobility of the Au and CNT nanocomposites, respectively. The disappearance of the depletion layer at the CNT interface, eliminated by the substrate temperature, enhances the Seebeck coefficient and thereby doubles the power factor, which is 502.72 μW·m–1·K–2 for the 300 °C-CNT-ZnO:Al film. The CNT composite has no effect on thermal conductivity. This results in the ZT improvement by 1.35 times (0.081 at 523 K). This nanocomposite method presents an effective and low-cost method to improve the ZT value of TE materials.

Microstructure and thermoelectric properties of the medium-entropy block-textured BiSbTe1.5Se1.5 alloy

“…The lattice thermal conductivity, k p , the electronic thermal conductivity, k e , and the bipolar thermal conductivity, k b , are usually contributing into the total thermal conductivity of semiconductors. The electronic thermal conductivity is related to the specific electrical conductivity, σ = 1/ρ, by the Wiedemann-Franz law [43].…”

Embedded Nanopattern for Selectively Suppressed Thermal Conductivity and Enhanced Transparency in a Transparent Conducting Oxide Film

“…Fig. 5c compiles reported figure of merit, FoM, values (ZT and ϕ TC ) for transparent conductive materials published the past 5 years [22,27,28,[46][47][48][49][50][51][52][53][54][55][56]. Red circles and blue triangles represent n-type and p-type materials, respectively.…”

Влияние углеродных нанотрубок на термоэлектрические свойства сплавов Гейслера p- и n-типа

“…Было показано, что УНТ значительно улучшают ZT теллуридов висмута n-типа [4,5], тогда как в материалах p-типа существенного повышения ZT не наблюдалось [6,7]. Наряду с этим, в литературе сообщалось об изучении влияния УНТ на термоэлектрические свойства MnSi 1.75 [9], Yb 0.3 Co 4 Sb 12 [10], α-MgAgSb [11], Bi 2 S 3 [12], SnTe [13,14], ZnO [15] и ряда полимеров [16][17][18].…”

“…Наиболее высокие значения термоэлектрической добротности были получены для половинных сплавов Гейслера, где удалось достичь ZT > 1 как в соединениях n-типа, так и в соединениях p-типа [19]. Учитывая растущий инте-рес к изучению влияния УНТ на термоэлектрические свойства материалов [7][8][9][10][11][12][13][14][15][16][17][18], для подобных исследований нами были выбраны материалы на основе половинных сплавов Гейслера Ni(Ti,Zr,Hf)Sn n-типа и Fe(Nb,Ta,Ti)Sb p-типа.…”