Solar inverters do not contain vacuum tubes. Where is the tungsten in a solar inverter? If you are an EE, you should be able to find this book in a technical l

Solar inverters do not contain vacuum tubes. Where is the tungsten in a solar inverter? If you are an EE, you should be able to find this book in a technical library or through interlibrary loan: "Photovoltaic Solar Energy: From Fundamentals to Applications" http://www.wiley.com/WileyCDA/WileyTitle/productCd-111892746X.html http://www.wiley.com/WileyCDA/WileyTitle/productCd-111892746... It is the most up-to-date book I know of that covers industrialized and up-and-coming PV technologies. There is only one mention of lithography in the book, on page 98. I quote: "There are several examples of small-area laboratory scale IBC [interdigitated back contact] solar cells, using three or more photolithography steps and vacuum-deposited metallization with measured one-sun efficiencies greater than 23%. ... " The rest of the section is about laboratory records from small cells and about how lithography is ill suited for mass production of full scale cells due to high costs. The trick to making market competitive IBC cells is avoiding lithography while keeping efficiency high. Most manufacturers do not even attempt to produce IBC cells, settling for slightly lower efficiency with significantly simpler manufacturing processes.