Innovative Production of Solar Modules by Epitaxial Technology

The long term aim of the project is to establish the production of solar cells based on a newly developed technology from Crystal Solar Inc. The production process is based on the so called Epitaxial Silicon growth technology (EPI) where silicon is deposited from the gas phase onto a substrate. The substrate can be used again after separation of the produced wafers. The production method reduces material consumption in production by up to 60 % and allows very thin wafers to be produced. In addition energy conversion efficiencies as high as 23,5% have been achieved with wafers from this process. This pilot project shall clarify issues regarding the scaling up of a surface treatment method tailored to the epitaxial wafers, and the development of an automation system for handling of the wafers. To ensure the progress of the project, the main parts of the allocated funds are used to develop necessary technology, previously proven in laboratory scale, to work in industrial applications. The pilot project will result in a revised application for funding of a main implementation phase by Borealis Solar. Automation and robotics for gentle handling of the substrate and produced wafers, further processing of cells and modules will be focus of WP4. Tronrud Engineering will be responsible for the implementation of WP4. Surface treatments of the epitaxial wafers will be the main focus area in WP2. The intended technology for the surface treatment will be scaled up to industrial-sized wafers. Norut Narvik will be the responsible and performing party in WP2.

The long term goal of the establishment of Borealis Solar AS is to start production of solar wafers, cells and modules by use of the epitaxial technology using two epitaxial reactor systems. The mono wafer is grown on top of a porous layer on a Si-substra te. Cell processing including surface etch, p-n junction and glass surface are performed on the wafers when they still are connected to the Si-substrate. When the cell processing is finished a vacuum based exfoliation process separating the cell and Si-su bstrate is performed. The cells are then edge shaped and backside processed before being assembled into PV-modules. Norut Narvik has developed new and improved concepts for cell front and backside processing including advanced recycling for process chemi cals. These techniques will be utilized to improve the pilot production plant of Borealis Solar in Narvik. Tronrud Engineering AS has been chosen to supply the project with the automation technology for the project. Tronrud will develop an automation con cept for Crystal Solar Epi tool layout, an automated system for EPI wafer handling, stacking of substrates in, retrieving the EPI-wafers out of the reactors and further to the front side polishing, substrate-wafer exfoliation separation and back side pass ivation. Narvik has been chosen as venue for the new company establishment due to the presence of suitable fabrication localities left from the REC and Inotec Solar Initiatives. The need for trained/skilled personnel may partly be met by recruiting stude nts as they are examined from HIN. HIN has already shown that they are capable of adjust the courses/educational packages to facilitate the demand from local corporate actors. As Norut Narvik AS already is established with a group within solar energy rese arch, they have been engaged by the project as "experts". Norut knowledge on front- and back-side treatment and chemical recycling are essential for the project to secure low cost production of solar cell modules.