Fine line printed silicon solar cells exceeding 20% efficiency
Silicon solar cells with passivated rear side and laser-fired contacts were produced on float zone material. The front side contacts are built rip in two steps, seed and plate. The seed layer is printed using all aerosol jet printer and a silver ink. After firing this seed layer through the silicon nitride layer, the conductive layer is growl) by light induced plating. The contact formation is studied on different emitter sheet resistances, 55 Omega/sq, 70 Omega/sq, and oil 110 Omega/sq. These emitters are passivated with a PECVD silicon nitride layer which also acts as all antireflection coating. Even oil the 110 Omega/sq emitters it was possible to reach a fill factor of 80.1%. The electrical properties i.e., the contact resistance of the front side contacts are studied by transfer length model (TLM) measurements. Oil a cell area of 4 cm(2) and emitter sheet resistance of 110 Omega/sq, a record efficiency of 20.3% was achieved. Excellent open-circuit voltage (V-oc) and short-circuit current (j(sc)) values of 661 in Valid 38.4 mA/cm(2) were obtained due to the low recombination in the 110 Omega/sq emitter and at the passivated rear sa face. These results show impressively that it is possible to contact emitter profiles with a very high efficiency potential using optimized printing technologies.