Abstract: Transparent, electrically-conductive, ion-blocking layers suitable for use in electrochromic windows. Preferably, one such layer is interposed between the electrochromic layer and its adjacent electron-conductive layer, and another such layer is interposed between the counter-electrode layer and its adjacent electron-conductive layer. Each of the transparent, electrically-conductive, ion-blocking layers comprises an n-type lithium-doped silicon carbide thin film formed by rf diode sputtering. In addition to being suitable for use in electrochromic windows, the n-type lithium-doped silicon carbide thin films of the present invention may also be used in a variety of electronic devices and may be combined, for example, with p-type silicon carbide films, either doped or undoped, in various p-n junction devices, such as LED's, high temperature diodes, etc.