An anti-reflection layer has been fabricated and applied in micromorph tandem (a-Si:H/mu c-Si:H) solar cells. In this work, the porous anti-reflection layers are produced on glass substrates by plasma enhanced chemical vapor deposition using a CF(4) and O(2) gas mixture. The process is simple and easily controlled. The tandem solar cells with the anti-reflection layer show the increased short-circuit current density of the solar cells due to increased light transmittance from air/glass interface. With the anti-reflection layer, the short-circuit current density of the tandem cell increases by 0.29 mA/cm(2). Meanwhile, the solar cell efficiency increases from 11.15% to 11.55% (3.5% in relative) which allows us to develop more efficient a-Si based solar cells. (C) 2011 Elsevier B.V. All rights reserved.