Abstract

In this paper the results on fabrication technology, structural, electrical characteristics of Nickel/Porous Silicon/Silicon (Ni/PS/Si) structures as direct Ammonia Solution (AS) fuel cells are reported. Here nano-porous silicon acts as proton conducting membrane, Ni as a catalyst layer with the thickness of 12-110nm in AS/Ni/PS/Si fuel cells. X-Ray Diffraction (XRD), electrical measurements and performance characteristics of AS/Ni/PS/Si cells were studied at room temperature. Generation of electricity was observed for Ni//PS/Si cells placed in Ammonia Solution (AS) in the range 0- 25%. Sharp rise of maximum power density (0.7mW/cm²) with the open-circuit voltage V=0.76V and the short-circuit current density J=2.4mA/cm², when nickel thickness decreases down to 12nm, was observed. Possible reason of this phenomenon is discussed on the basis of quantum size effect which may occur at ultrathin thickness of the catalyst..

Keywords:Nano-nickel/porous silicon fuel cell; Ammonia electrolyte; Maximum power density; Open-circuit voltage