High efficiencies on large area screen printed silicon solar cells and contacting high sheet resistance emitters using hotmelt ink
This paper presents an update on current investigations of the hotmelt technology at Fraunhofer ISE. Efficiencies up to 18% with fill factors of 79.5% on large area industrially pre- processed monocrystalline wafers were achieved. In order to further increase the efficiency, Voc and jsc need to be improved, by e.g. reducing the doping level of the emitter. Solar cells with an average emitter sheet resistance up to 75 Î/sq could be successfully contacted with hotmelt ink achieving fill factors up to 78%. These cells clearly showed an improvement in the short circuit current density compared to solar cells with a higher doped emitter. In a further investigation the ability of fine line printing has been analyzed.