Kelvin Probe Force Microscopy (kpfm): Investigation of Local Boron Doped Emitter Regions Formed by Inkjet Boron Inks for Industrially Feasible Ibc Solar Cells

Solar cell concepts like the IBC concept based on locally doped areas promise a high efficiency of more than 24%. This, however, imposes two major challenges: the capability to create these locally doped regions and – which is often forgotten – the capability to check the actual electronic quality of these sometimes microscopic regions (doping level etc.). In order to keep manufacturing costs small, the approach of local doping by ink jetting boron-containing inks is chosen for this contribution. Though liquid deposited doping sources exhibit inhomogeneous properties by itself, the spatial resolved quality control is of utmost importance. Therefore, Kelvin probe force microscopy (KPFM) is applied to map the surface potential and thus the local doping level. Using this technique, some special features of ink jetted boron-containing inks and driven-in emitters like edge sharpness, dopant distribution among other topics are discussed.