Hydrogenated carbon nitride (a-CNx:H) films (0-500 nm) were deposited on p-Si wafers to make Au/a-CNx: H/p-Si photovoltaic cells using i-C4H10/N-2 supermagnetron plasma chemical vapor deposition. At a lower electrode RF power (LORF) of 50 W and an upper electrode RF power (UPRF) of 50-800 W, hard a-CNx:H films with optical band gaps of 0.7-1.0 eV were formed. At a film thickness of 25 nm (UPRF of 500 W), the open circuit voltage and short circuit current density were 247 mV and 2.62 mA/cm(2), respectively. The highest energy conversion efficiency was 0.29%. The appearance of the photovoltaic phenomenon was found to be due to the electron-transport and hole-blocking effect of thin a-CNx:H film. (C) 2009 Elsevier B.V. All rights reserved.