Amorphous SiC:H (a-SiC:H) diode structures with different ratios of Si:C are deposited on transparent conductive boron-doped diamond-coated fused silica substrates by plasma-enhanced chemical vapor deposition. The boron-doped diamond thin films have been deposited at temperature 720 °C on the fused silica substrates with a Ti grid used to enhance electrical conductivity. The thin-film structures based on P-type, Intrinsic and N-type a-SiC:H thin films, shortly a-SiC:H PIN diodes, are characterized by current–voltage measurements under solar simulator illumination. For comparison, the same PIN structures are deposited on fluorine-doped tin oxide. Before deposition of the diode structures, the surface morphology is studied by scanning electron microscopy, and undoped layers deposited on the quartz substrates are characterized by temperature-resolved electrical resistivity, optical absorptance, Raman spectroscopy, and photoluminescence.