We report the vectorially controlled and well-aligned Si nanowires (SiNWs) array with enhanced optical absorption property in large area grown by the vapor-liquid-solid (VLS) mechanism as controlling the temperature gradient (TG) on the growth substrate. We demonstrate that the growth direction and magnitude of the SiNWs are quantitatively controllable in parallel and proportional to the locally imposed TG. We also show explicit examples of the vectorially controlled 3-dimensional NW growth on contoured or patterned substrates in the presence of the TG. The aligned SiNWs array shows excellent optical absorbance over a broad range of wavelength of 350-750 nm, which provides a practical implication of the well-ordered SiNWs system. (c) 2012 Elsevier B.V. All rights reserved.