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For many years, the selective emitter approach has been well-known to yield cell efficiencies well above those achieved by conventional screen-printed cells. A simple and effective way of forming a selective emitter can be achieved by laser doping to simultaneously pattern the dielectric with openings as narrow as 8 m, and create heavy doping beneath the metal contacts. In conjunction with laser doping, light-induced plating (LIP) is seen as an attractive approach for forming metal contacts on the laser-doped regions, without the need for aligning masks or other expensive, long laboratory processes. As laserdoping is gaining increasing interests in the PV industry, selection of the most appropriate laser and processing conditions is important to ensure high yields in a production environment. In this work, we have identified a suitable laser that enables good ohmic contacts for a wide range of laser scan speeds. Sheet resistances of laserdoped lines as low as 2 ohms/sq was achieved at a scan speeds of <1 m/s, while a sufficiently high doping (~20 ohms/sq) is still achievable at scan speeds up to 6 m/s. Optimization of the laser parameters in this work lead to a cell efficiency of 18.5% being achieved with the laserdoped selective emitter (LDSE) structure. The cell also has an excellent pseudo fill factor (pFF) of 82.3% and a local ideality factor n nearing unity. This indicates there is minimal laser-induced damage and junction recombination as a result of the laser doping process.

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Q‐switched infrared, green, UV and DUV lasers are being used routinely for various microelectronics and photovoltaic manufacturing applications, such as ablation and cutting of dielectric materials, LED scribe and cleave processes in microelectronics, and scribing thin film solar cells. To create functional good results when micromachining any material, the laser energy density needs to be set higher than the material removal threshold and a reasonable laser beam spot overlap is required. The maximum scribing speed achieved using a system with a pulsed laser source therefore is usually limited by the laser repetition rate and the energy per pulse available at that repetition rate. For a given repetition rate, as processing speed increases the beam spot overlap decreases and at certain critical processing speed laser beam spots gets separated in space and continuous scribing of material is not possible. This fundamental limitation has to be solved in order to achieve faster processing speeds, higher throughput, and lower cost per part. To overcome this limitation in next generation laser processing systems, SpectraPhysics has developed and evaluated high repetition rate mode‐locked lasers as an alternative to Q‐switched lasers. Using a high average power mode‐locked laser operating at 80 MHz, we have been able to demonstrate processing speeds that are an order of magnitude higher in thin layers of select materials than that with current Q‐switched technology. The following article reviews results obtained for micromachining dielectrics, scribing and cleaving blue LEDs, and scribing different solar cell materials.