Improved process for the manufacturing of back contact integrated cooling channels for concentrator solar cells

Cooling of CPV devices is one of the essential issues to enable the full exploitation of the advantages of light concentration. To address the problem of cooling CPV devices this research work proposes an improved method for the processing of back metallization integrated microcoolers for photovoltaic devices. The back metallization integrated microcooler has the advantage of not being applicable for a wide variety of semiconductor solar cell and not requiring any TIM material. The proposed process is based on the evaporation of a titanium and copper dual layer with subsequent photoresist patterning and electroplating of copper around the photoresist pattern to form the cooling microchannels in the back metallization. The improvement of the process is the introduction of an intermediate seed layer that is deposited after thickness of the electroplated copper has reached the photoresist thickness. This additional seed layer will increase process speed since closing of the channels will not depend on the lateral growth of the electroplated copper any more.