Effects of Electroformed Fe-Ni Substrate Textures on Light-trapping in Thin Film Solar Cells

Abstract

Electroforming can be used to separate electrodeposited metal from the surface of a metal or other conductive material to produce new metallic products with fine shapes. Because Si thin-film solar cells possess fewer absorption layers than other compound thin-film solar cells, light-trapping technology is required to increase the rate of light absorption. Various metal substrate shapes can be constructed in the electroforming process, depending on the shape of the mandrel surface. The objective of this study was to construct specific textured substrates through electroforming to improve light-trapping efficiency in silicon (Si) thin-film solar cells. We constructed pyramid-and V-shaped substrates at angles of 30°, 45°, and 60° by electroforming. To observe the reflective properties of the manufactured substrates, we used an ultraviolet/visible (UV/Vis) spectrometer to measure the total and diffused reflectance. We found that an increase in the contact angle due to changing texture led to a decrease in total reflectance in Fe-Ni alloy substrates. We concluded that substrate texture led to an increase in the light paths in the light-absorbing layers of the thin-film solar cells.

Correlation between the bath composition and nanoporosity of DC‐electrodeposited Ni‐Fe alloy

“…The deposition process was conducted under a DC condition (60 mA cm −2 ). First, nc Ni‐49 at% Fe alloy films were deposited over the cathode surface at thicknesses of up to 200 ± 10 μm and then mechanically stripped as free‐standing foils 9 . Subsequently, the as‐deposited foils were annealed in an H 2 + N 2 gas atmosphere at 320, 350 and 370°C at a 5°C/min heating rate, and this was followed by a 60‐min holding time to thermally stabilise the nc alloys.…”

“…1 The potential applications of nc Ni-Fe alloys range from micro-electro-mechanical systems to solar cells, organic light-emitting diodes, magnetic devices and functional coatings, in force of their unique magnetic, thermal and mechanical properties. [2][3][4][5][6][7][8][9] Despite the versatility of the electrodeposition process, in terms of alloy types, chemical compositions, microstructure and properties, 1 process control is difficult as a result of such factors as the bath composition, current density, pH and temperature. The fabrication of nc Ni-Fe alloys by means of the DCelectrodeposition process, in its simplest form, utilises a constant current density ( j).…”

“…Electrodeposition is a viable and low‐cost manufacturing technology of nanocrystalline (nc) thin films and free‐standing foils of controlled composition, purity, grain size and thickness 1 . The potential applications of nc Ni‐Fe alloys range from micro‐electro‐mechanical systems to solar cells, organic light‐emitting diodes, magnetic devices and functional coatings, in force of their unique magnetic, thermal and mechanical properties 2‐9 . Despite the versatility of the electrodeposition process, in terms of alloy types, chemical compositions, microstructure and properties, 1 process control is difficult as a result of such factors as the bath composition, current density, pH and temperature.…”

Reproduction of Biomimetic Structural Colors via µm‐Scale Ni Textures

“…This electroforming process can manufacture metallic products in fine shapes (µm to mm scale) by separating the electrodeposited metal from the surface of a metal or a conductive material. [ 29,30 ] Thus, it has been reported that the metal products with complex and precise patterns were fabricated on a large scale by the electroforming method using Ni, Cu, Au, and Fe‐Ni alloys. [ 31–33 ]…”

“…[1][2][3] Structures with sizes comparable to the wavelengths of incident light selectively diffract the light to cause constructive or destructive shapes (µm to mm scale) by separating the electrodeposited metal from the surface of a metal or a conductive material. [29,30] Thus, it has been reported that the metal products with complex and precise patterns were fabricated on a large scale by the electroforming method using Ni, Cu, Au, and Fe-Ni alloys. [31][32][33] Therefore, we developed the Bragg stacked Ni textures with a µm pitch to cost-effectively reproduce biomimetic structural colors of the Papilio Palinurus on a large scale.…”