APPLIED PHYSICS LETTERS, cilt.98, sa.20, 2011 (SCI-Expanded)
Semiconductor nanopillar arrays with radially doped junctions have been widely proposed as an attractive device architecture for cost effective and high efficiency solar cells. A challenge in the fabrication of three-dimensional nanopillar devices is the need for highly abrupt and conformal junctions along the radial axes. Here, a sulfur monolayer doping scheme is implemented to achieve conformal ultrashallow junctions with sub-10 nm depths and a high electrically active dopant concentration of 10(19)-10(20) cm(-3) in arrays of InP nanopillars. The enabled solar cells exhibit a respectable conversion efficiency of 8.1% and a short circuit current density of 25 mA/cm(3). The work demonstrates the utility of well-established surface chemistry for fabrication of nonplanar junctions for complex devices. (C) 2011 American Institute of Physics. [doi:10.1063/1.3585138]