Screening charges between the p-Si and a-TiO2 through insertion of a metallic interlayer required two energetic considerations. First, the metallic contact to p-Si had to be rectifying, and second, the metallic contact to a-TiO2 had to be ohmic. This was achieved using a metallic Ti layer, which was sputtered on the p-Si substrate before deposition of the a-TiO2 through ALD. After subsequent deposition of a Pt catalyst, the devices could be operated as a PEC for the HER. Significant light attenuation was introduced into the device due to this metallic interlayer, which was overcome by increasing the incident illumination to the equivalent of 1.5 suns at the front of the electrochemical cell to reach similar photocurrents as with the standard devices.