Interdigitated back contact silicon solar cells with laser fired contacts

We report on interdigitated back-contact silicon solar cells with efficiencies above 18%, fabricated using laser fired silver for both base and emitter contacts. While laser fired aluminum contacts have been reported in the past, this is the first report to our knowledge describing a single-step laser process to dope the underlying silicon and create a point contact at the same time. Conventional industrial processes were used for texture, emitter diffusion and passivation. Dopant and metal grids for base and emitter were printed using high-throughput screen-printers. The best cell showed 632mV Voc, 39.7 mA/cm2Jsc, and fill-factor of 0.72.