<li>'''Thin film modules:''' Thin film modules are built out by laying photovoltaic material in one or more layers on a supporting material such as glass, plastic, or metal. Thin film modules come in various types with Cadmium-Telluride (CdTe) Being the most common. CdTe modules contain far less aluminum and more glass than Crystalline silicon modules (average by weight): 97% glass (panel surface), ~3% polymer (junction boxes and sealant) and negligible amounts of semiconductors and metals. <ref name="irena" /> Thin film modules are far less efficient than crystalline silicon modules at around 9% efficiency, but significantly cheaper.</ol>
