A study into the formation and characterisation of electroless nickel silicide for laser doped solar cells
In this paper we will study the formation and characteristics of nickel silicide compounds and the subsequent specific contact resistivity (Ω.cm2) during the formation of an ohmic contact in solar cells. Using Transmission Line Method (TLM) we will analyse the electrical characteristics of the formed nickel silicides at different sintering temperatures and durations. In each sintering condition tested, the relationship between the total resistance and the distance between the contact pads on the fabricated test structures is measured and graphed. From these graphs the contact resistance (Ω) and specific contact resistivity (Ω.cm2) of the metallisation stack is calculated and tabulated. We conclude the paper by showing the optimum sintering condition of 350°C for three minutes for laser doped solar cells which yields negligible contact resistance.
Diffusion layers and the Schottky-barrier height in nickel silicide-silicon interfaces
On montre, par diffraction d'electrons lents, par microscopie electronique en transmission, et par emission photoelectronique a partir des interfaces, qu'une couche de diffusion est toujours presente apres avoir forme des interfaces de siliciure de nickel sur des surfaces Si. Cette couche est une phase metallique ordonnee riche en silicium. L'invariance de la hauteur de la barriere de Schottky pour les interfaces de siliciure de nickel est attribuee a cette couche. Les problemes de croissance selective planaire sont discutes
Residual stresses and texture in Ni/SiC nanocomposite coatings
Abstract Nanocomposites of Ni–SiC were electrodeposited on a 2024-T3 aluminum substrate in a nickel sulfamate bath. The goal of the study was to determine the effect of the SiC particle size and concentration on the crystallographic texture and residual stresses that develop in the nickel matrix. The presence of crystallographic texture, its nature, and its intensity affect all mechanical and physical properties of the coating. Residual stresses, if highly tensile, may be detrimental to the performance of the nanocomposite coating. The texture and residual stresses evolving in the coatings were studied using X-ray diffraction. Composites with nano-particles developed a strong 〈1 0 0〉 fiber texture and stresses that were compressive in small SiC concentrations, but tensile with low magnitude at greater concentrations. The composite with coarser SiC (500 nm) demonstrated a very weak 〈1 1 1〉 texture and residual stresses that are tensile in nature. Based on the findings, nanocomposites are expected to perform better than micro-composites that were electroplated using the same coating parameters.