The solar light harvesting has long been regarded as promising way to meet the increasing world's annual energy consumption as well as the solution to prevent the detrimental long-term effect of carbon-monoxide emission released by fossil fuel sources. Due to the high cost of today's conventional PV technology, however, it is not possible to compete with the energy supplied from fossil fuel sources. The use of one-dimensional nanostructures, including nanowires (NWs), nanorods (NRs), nanopillars (NPs) and nanotubes (NTs) in solar cells with different device architectures (e.g. axial, radial, and nanorod/nanowire array embedded in a thin film) provides peculiar and fascinating advantages over single-crystalline and thin film based solar cells in terms of power conversion efficiency and manufacturing cost due to their large surface/interface area, the ability to grow single-crystalline nanowires on inexpensive substrates without resorting to complex epitaxial routes, single-crystalline structure and light trapping function. In this chapter, we review the recent studies conducted on nanowire/nanorod arrays based solar cells with different device architectures for the realization of high-efficiency solar cells at an economically viable cost.