beta-FeSi2 and Al were magnetron-sputtered onto n-Si(001) substrates and annealed by rapid thermal processing to form beta-FeSi2(Al) thin films. The Al was incorporated through co-sputtering with beta-FeSi2 and also as an interlayer between the co-sputtered film and Si substrate. FeSi2(Al) with atomic ratio of Al between 0.14 and 0.37 was polycrystalline, orthorhombic and semi-conducting. beta-FeSi2(Al)/Si heterojunction solar cells were fabricated and characterized for photovoltaic properties. Under AM 1.5G, 100 mW/cm(2) illumination, devices prepared with Al interlayers (1.5 to 9 nm thick) exhibited short-circuit current and open-circuit voltage improvement over device without interlayer. Spectral response measurements revealed that photocarriers contribution from beta-FeSi2(Al) film and Si in the 300-700 nm and 700-1200 nm regions respectively, increased with Al concentration. The improvement in photovoltaic performance can be correlated to sharper FeSi2(Al)/Si interface for device with 1.5 nm thick Al interlayer and reduced dark current for 9 nm Al interlayer. (C) 2011 The Electrochemical Society. [DOI: 10.1149/2.063201jes].