Natcore Technology has announced that its R&D Center in Rochester, N.Y., has created an all-low-temperature, laser-processed solar cell. The company says this development sets the stage for a marriage between Natcore's laser processing and its black silicon technology and could lead to gains in efficiency and significantly lower production costs.
According to Natcore, current silicon processing techniques involve temperatures of 850 degrees C (1,562 degrees F) or higher. However, Natcore says its process does not entail temperatures above 350 degrees C for any step. The company adds that 350 degrees C is a common annealing temperature used in industry, whereas exposure to 850 degrees C and above, the temperature typically used for conventional solar cells, requires specialized equipment.
For example, processing at the higher temperature is done in some form of a diffusion furnace, the interior of which needs to be fabricated from quartz or other very high-temperature compatible materials like silicon carbide. Natcore says its process eliminates that diffusion furnace altogether and, thus, helps save costs.
‘Applying a black silicon etch is a very inexpensive antireflective process,’ says Chuck Provini, Natcore's president and CEO. ‘Laser processing is also relatively low cost, because it reduces energy and chemical costs associated with the furnace that it replaces. By combining two low-cost, low-temperature processes, Natcore is effecting a paradigm change as to how solar cells are made. We believe that our proprietary technology will be in great demand, and we will move to license it to the right partner as soon as possible.’
The next steps in the development will be to add Natcore's black silicon antireflection control technology to the front of the cell and to move the front contacts to the back of the cell in what is called an interdigitated contact pattern. The company says eliminating the front contacts will allow a 3% to 4% more light to enter the cell and increase its output.