Methods and apparatus are provided for converting electromagnetic radiation, such as solar energy, into electric energy with increased efficiency when compared to conventional solar cells. A photovoltaic (PV) device may incorporate front side and/or back side light trapping techniques in an effort to absorb as many of the photons incident on the front side of the PV device as possible in the absorber layer. The light trapping techniques may include a front side antireflective coating, multiple window layers, roughening or texturing on the front and/or the back sides, a back side diffuser for scattering the light, and/or a back side reflector for redirecting the light into the interior of the PV device. With such light trapping techniques, more light may be absorbed by the absorber layer for a given amount of incident light, thereby increasing the efficiency of the PV device.