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The interfacial property between thermoelectric films and metal electrodes greatly affects the performance and practical application of thin‐film thermoelectric devices. Here, Ni intermediate layer is chosen and inserted into Bi2Te3/Cu to simultaneously regulate the electrical and mechanical performance of the interface. Meanwhile, Ar/H2 plasma cleaning is also adopted to optimize the interfacial connection during the sputtering process. Results show the interfacial element diffusion can be effectively blocked after the introduction of Ni interlayer, and the Bi2Te3/Ni/Cu multilayer thin film performs an excellent interfacial adhesion and maintains a low specific contact resistivity about 2.7 × 10−6 Ω cm2, which can be attributed to the matching of thermal expansion coefficient between Bi2Te3, Ni, and Cu, and the reduction of lattice mismatch. Furthermore, the Ni interlayer can also alleviate the degradation of interfacial mechanical and electrical properties after 1000 cycles of thermal shock, consequently enhancing the reliability and stability of the interfacial connection. This work provides an effective way to improve the comprehensive performance of multilayer interface in thin‐film thermoelectric devices.

wileyonlinelibrary.comand short-wavelength spectral response is not good enough, mainly due to the large recombination loss of back surface fi eld (BSF) [ 2 ] and the high residual refl ectance at the front surface, [ 3 ] respectively. To achieve the excellent broadband spectral response of the Si based solar cells, it is necessary to further improve the optical and electrical properties of the rear surface as well as the front surface. By introducing passivation dielectric thin fi lms at the rear surface, Green group [ 4 ] has successfully fabricated a 22.8% effi cient passivated emitter and rear cell (PERC) with an area of 4 cm 2 , manifesting superior long-wavelength spectral response due to the low recombination velocity and high long-wavelength refl ectivity at the rear surface. [ 5 ] This longwavelength superiority has been recently employed in the photovoltaic industry for the mass production of 20.0% effi cient PERCs on commercial large-area (156 × 156 mm 2 ) Si wafers. [ 6,7 ] On the other hand, Si nanostructure array provides a promising approach to enhancing the energy harvesting in the shortwavelength range, for the near zero and small-angle-dependent refl ectivity in the short-wavelength region. [8][9][10][11][12][13][14][15] By employing the well short-wavelength antirefl ection of the Si nanostructure array, many authors have made relative progresses in the cell performances of the Si nanostructures based solar cells. [16][17][18][19][20][21] But η 's of these Si nanostructures based solar cells are still not satisfi ed when comparing with those of the traditional solar cells, which is mainly attributed to the large surface recombination loss from the Si nanostructures. Surface passivation such as thermal SiO 2 , [ 4,11,22 ] SiN x :H by plasma enhanced chemical vapor deposition (PECVD), [ 23,24 ] and Al 2 O 3 by atomic layer deposition (ALD) [25][26][27] can effectively suppress the surface recombination by saturating the dangling bonds or forming the fi xed charges at and near the surface. Particularly, the stack SiO 2 /SiN x layers provide an excellent passivation for the Si nanostructures, [28][29][30] which benefi ts from the well surface passivation of the inner SiO 2 as well as the bulk passivation of the outer SiN x :H. The simultaneous surface and bulk passivation guarantee the well electrical performance of the Si nanostructures based solar cells.As a result, the passivated front Si nanostructures together with the passivated rear surface are able to provide the complementary spectral responses in both the short-wavelength and long-wavelength region, implying an effective way to achieve the excellent broadband spectral response of Si based solar cells. In this paper, 20.0% Effi ciency Si Nano/Microstructures Based SolarSpectral response of solar cells determines the output performance of the devices. In this work, a 20.0% effi cient silicon (Si) nano/microstructures (N/M-Strus) based solar cell with a standard solar wafer size of 156 × 156 mm 2 (pseudo-square) has been successfully fabrica...

Chemical vapor deposition (CVD) on Cu foils emerged as an important method for preparing high-quality and large-area graphene films for practical applications. However, to date it remains challenging to rapidly identify the structural features, especially the layer numbers, of CVD-graphene directly on Cu substrate. Herein, we report an O 2 -plasma-assisted approach for identifying the coverage, wrinkles, domain size, and layer number of large-area graphene films on Cu foils by optical microscopy. The wrinkles and grain boundaries of five-layer graphene can be observed with a grayscale increment of ∼23.4% per one graphene layer after O 2 -plasma treatment for only 15 s, which allows for checking graphene on Cu foils with a sample size of 17 cm × 20 cm in a few minutes. The Raman spectroscopy and X-ray photoelectron spectroscopy presents a strong layer number dependence of both the plasma induced graphene defects and Cu oxides, which, as indicated by molecular dynamic simulation, is responsible for the improved image contrast as a result of the interaction between O-ions and graphene with different layer numbers. We expect that this O 2 -plasma-assisted method would be applied to meter-scale samples if atmospheric-pressure plasma is used and therefore will be beneficial for the fast evaluation of CVD-graphene in both laboratory and industry.

Nickel and antimony co-doped Ti/SnO 2 (Ti/Ni-Sb-SnO 2 ) anodes were prepared by spray pyrolysis. Effects of nickel concentration on the structure and onset potential for oxygen evolution of Ti/Ni-Sb-SnO 2 anodes have been systematically investigated.XRD analyses suggest that SnO 2 thin films grow in preferential orientation along (101) plane as the nickel concentration increases. The enhanced onset potential of oxygen is above 2.4 V vs NHE due to the introduction of nickel doping, and increases slightly with the nickel concentration. The calculated results show that work function of Ni/Sb co-doped SnO 2 also increases with the Ni doping level, which contributes to the enhancement of onset potential for oxygen evolution.