Series of nickel-passivated porous silicon were fabricated by hydrothermally etching single crystal silicon wafers under different etching conditions. Morphology and photoluminescence (PL) investigation are disclosed that there exist strong correlation between the characteristics of the surface morphology and PL, i.e., the samples prepared with lower Ni~(2 ) concentration are exhibited more regular surface morphology, stronger PL, as well as narrower PL band. The possibility of the realization of the PL improvement through controlling the surface morphology of porous silicon is also explored.