Transparent conductors with an ultrathin nickel layer for high-performance photoelectric device applications

A thin nickel (Ni) layer of thickness 5 nm was inserted in between the indium tin oxide (ITO) layers of thickness 50 nm each so as to increase the conductivity of ITO without affecting much of its transmittance nature. ITO layers with and without Ni film were prepared by reactive DC sputtering on both Si and glass substrates. The influence of Ni layer on the optical and electrical properties of prepared devices was investigated. Due to the insertion of thin Ni layer, the resistivity of ITO/Ni/ITO sample (3.2×10−4 Ω cm) was reduced 10 times lesser than that of ordinary ITO layer (38.6×10−4 Ω cm); consequently it increased the mobility of ITO/Ni/ITO device. The external and internal quantum efficiencies (EQE and IQE) of ITO/Ni/ITO device exhibited better performance when compared to ITO layer that has no Ni film. At wavelengths of 350 and 600 nm, the photoresponses of ITO/Ni/ITO device were predominant than that of reference ITO device. This highly conductive and photoresponsive Ni inserting ITO layers would be a promising device for various photoelectric applications.