The high refractive index of silicon requires efficient broad band anti-reflection (AR) measures to reduce Fresnel reflection losses. Commercial standard silicon solar cells rely on surface textures created by random anisotropic etching, which still is time-consuming and only applicable to the monocrystalline material. At this stage, the black silicon fabricated by ICP-RIE could offer a solution that combines both broadband AR properties and strong near band gap light trapping. The optical and electronic properties of monocrystalline Si (100) with a nanostructured surface obtained by an inductively coupled plasma (ICP) dry reactive ion etching (RIE) process in a gas mixture of SF₆ and O₂, were improved with regard especially to solar cell applications. Al₂O₃ and Al:ZnO thin films were grown on highly doped p-Si (100) and n-Si (100) black silicon respectively by atomic layer deposition (ALD) using trimethylaluminum (TMA) and water as precursors for Al₂O₃ thin film, and methylzincisopropoxide (MZI), dimethylaluminium isopropoxide (DMAI) and water as precursors for Al:ZnO thin film. The morphology of the deposited films and initial black silicon (silicon grass) were investigated by means of reflection electron microscopy (REM). X-ray photoelectron spectroscopy (XPS) was used to analyze the chemical elemental composition by observing the behavior (stoichiometry) of the Zn 2p, Al 2p, O 1s and C 1s lines of three samples. Binding energy analysis and calculated Auger parameter confirmed the formation of conformally Al₂O₃ and Al:ZnO on the black silicon samples.