High efficiency a-Si:H/a-Si:H solar cell with a tunnel recombination junction and a n-type μc-Si:H layer

► The p-μc-Si:H tunnel junction improves Voc and FF in the a-Si:H/a-Si:H solar cells. ► The matched current leads the highest initial and stabilized efficiency. ► The n-μc-Si:H layer improves Jsc, FF and Voc in multi-junction solar cells. ► An initial efficiency of 10.29% (stabilized efficiency = 8.54%) is achieved.