Lasers are widely used for production of photovoltaic cells. Oxford Lasers manufactures a wide range of systems for solar cell production and R&D. These range from simple edge isolation systems to leading edge EWT and MWT drilling systems.
Oxford Lasers Solar Cell manufacturing systems include:
LaserFire: Laser Fired Contact Production System
Lasers can used to create conduction paths through an insulating layer on the back face of a photovoltaic cell. A single laser pulse heats a small spot on the aluminium layer. The heating punctures the insulating oxide or nitride layer and creates an electrical contact to the silicon. By running the laser at a high repetition rate and scanning the beam across the surface a large number of Laser Fired Contacts can be produced in a very short time.
LaserFire systems are designed for the production of laser fired contacts on crystalline silicon photovoltaic cells. They can be used at very high speed to process a cell in a few seconds. Alternatively the LaserFIre can be run in ultra high precision mode to allow very precise positioning of the laser spots. This allows the contacts to be accurately aligned with other features on the cell.
LaserGroove: Laser Grooved Buried Grid Production System
Lasers can be used to machine a network of narrow grooves across the front surface of a solar cell. These grooves are metallised to create a low resistance front contact on the photovoltaic cell.
The LaserGroove systems from Oxford Lasers allow grooves to be produced at high speed with accurate control of grove depth and width.
LaserEdge: Edge Isolation System
During the manufacturing process a conduction path is created between the front and back surfaces of the wafer, all around the edge. This is commonly removed by scribing a channel in the surface of the wafer.
The LaserEdge system from Oxford Lasers allows the edge isolation process to be carried out at high speed with very good control of the scribe width and depth.
SolarDrill: Solar Cell Drilling System
Two techniques being explored for the production of high efficiency solar cells are Emitter Wrap Through (EWT) and Metallisation Wrap Through (MWT. These related techniques rely on laser drilled holes to provide the connection between the front surface of the cell and busbars on the rear face.
SolarDrill systems from Oxford Lasers provide very high speed drilling of micro-holes across the surface of the wafer. The taper can be controlled to give the correct hole profile for plating or doping.