Thermoelectric Properties of Cu2Se Nano-Thin Film by Magnetron Sputtering

Abstract

Thermoelectric technology can achieve mutual conversion between thermoelectricity and has the unique advantages of quiet operation, zero emissions and long life, all of which can help overcome the energy crisis. However, the large-scale application of thermoelectric technology is limited by its lower thermoelectric performance factor (ZT). The thermoelectric performance factor is a function of the Seebeck coefficient, electrical conductivity, thermal conductivity and absolute temperature. Since these parameters are interdependent, increasing the ZT value has always been a challenge. Here, we report the growth of Cu2Se thin films with a thickness of around 100 nm by magnetron sputtering. XRD and TEM analysis shows that the film is low-temperature α-Cu2Se, XPS analysis shows that about 10% of the film’s surface is oxidized, and the ratio of copper to selenium is 2.26:1. In the range of 300–400 K, the maximum conductivity of the film is 4.55 × 105 S m−1, which is the maximum value reached by the current Cu2Se film. The corresponding Seebeck coefficient is between 15 and 30 µV K−1, and the maximum ZT value is 0.073. This work systematically studies the characterization of thin films and the measurement of thermoelectric properties and lays the foundation for further research on nano-thin-film thermoelectrics.

Au@Cu2O Core–Shell and Au@Cu2Se Yolk–Shell Nanocrystals as Promising Photocatalysts in Photoelectrochemical Water Splitting and Photocatalytic Hydrogen Production

“…In Figure S4, the XPS spectra of Cu 2p and O 1s for pure Cu 2 O showed spectral features with binding energies complying with the chemical states of Cu 2 O nanocrystals. , Compared to pure Cu 2 O, a perceivable binding energy shift of Cu 2p and O 1s (approximately 0.2 eV for Cu 2p and 0.1 eV for O 1s) was observed for Au@Cu 2 O, suggesting that pronounced electronic interactions occurred between Au and Cu 2 O . As expected, the binding energies of Cu 2p and Se 3d for pure Cu 2 Se were also consistent with the reported values of Cu 2 Se nanocrystals . The noticeable binding energy shift observed for Au@Cu 2 Se (approximately 0.3 eV for Cu 2p and 0.1 eV for Se 3d) also revealed significant electronic interactions therein.…”

Realizing high thermoelectric performance in highly (0l0)-textured flexible Cu2Se thin film for wearable energy harvesting

“…As shown in Fig. 4 (g), the high PF is higher than that of other reported films deposited by different methods [17-20, 25, 32-34], including sputtering [17,32], thermal evaporation [18], pulsed laser deposition [19], solution immersion method [20], sputtering combined with thermal evaporation method [25], ion beam sputtering [33], spin coating process [34]. The high PF is also comparable with that of Cu2Se bulk (PF=12.52 μWcm -1 K -2 ) reported by Yu et al.…”

“…Therefore, Cu2Se provides an exciting commercial opportunity as a potential substitute for fabricating high-efficiency and low-cost flexible thin-film devices. Many works focused on obtaining high-performance Cu2Se thin films have been reported in recent years [17][18][19][20][21]. To data, carrier engineering is the most effective method to improve the TE performance of Cu2Se thin films.…”

Optical band gap, photocatalysis, surface structures and depth profile properties of Cu2Se nanostructured thin films

“…There exist a number of techniques to prepare Cu 2 Se thin films including thermal evaporation (Yadav et al 2020), Sputtering (Yang et al 2021b), Selenization (Gadjiev et al 2016), Solvothermal (Lin et al 2009), Galvanic synthesis (Yang and Hu, 2008) and chemical bath deposition (Sohrabi and Ghobadi, 2019). When compared to the techniques mentioned, electrochemical deposition is rapidity, low cost, free from porosity, high purity, easy to control alloy composition and its industrial applications (Grozdanov, 1994).…”