Backside contacted solar cells with heterojunction emitters and laser fired absorber contacts for crystalline silicon on glass

Backside contacted cells were fabricated on p- and n-type, liquid phase crystallized silicon on glass. The heterojunction emitter and transparent contacting layer were opened locally using an inkjet printer and the absorber was contacted with laser fired point contacts. An analytical resistance model was derived to determine the resistance losses for the point contact geometry. Using test structures and the model it was found that for p-type cells the main contribution to the cell resistance came from the absorber contact and the absorber. Both were strongly reduced by increasing the absorber doping. For n-type cells the main contributions originated from the emitter and emitter-TCO contact, which was improved by changing the emitter type, resulting in an 11.6 % solar cell.