I. Introduction
The main challenge in today's photovoltaics industry is to increase the conversion efficiency and to lower the production cost of cells. A route towards higher efficiency is the implementation of selective emitter (SE) and local back surface field (LBSF) structures into silicon solar cells. A SE can reduce contact resistance by being heavily doped under the metal contacts, while ensuring low recombination elsewhere by being lightly doped in optically active regions, which results in a higher fill factor (FF) and a better blue response. A heavily doped LBSF can also increase the fill factor due to a decreased series resistance and rear-side recombination. State-of-the-art high efficiency silicon solar cells, such as the passivated-emitter rear locally diffused (PERL) cell, were fabricated with locally doped regions at front and rear sides [1]. However, the approach to realize local doping requires cost-intensive and time-consuming processes such as photolithography and high temperature diffusions, which prevents the integration of these cell concepts into industry mass production.