A new tunnel recombination junction is fabricated for n–i–p type micromorph tandem solar cells. We insert a thin heavily doped hydrogenated amorphous silicon (a-Si:H) p + recombination layer between the n a-Si:H and the p hydrogenated nanocrystalline silicon (nc-Si:H) layers to improve the performance of the n–i–p tandem solar cells. The effects of the boron doping gas ratio and the deposition time of the p-a-Si:H recombination layer on the tunnel recombination junctions have been investigated. The current-...","A new tunnel recombination junction is fabricated for n-i-p type micromorph tandem solar cells.We insert a thin heavily doped hydrogenated amorphous silicon (a-Si:H) p+ recombination layer between the n a-Si:H and the p hydrogenated nanocrystalline silicon (nc-Si:H) layers to improve the performance of the n-i-p tandem solar cells.The effects of the boron doping gas ratio and the deposition time of the p-a-Si:H recombination layer on the tunnel recombination junctions have been investigated.The current-voltage characteristic of the tunnel recombination junction shows a nearly ohmic characteristic,and the resistance of the tunnel recombination junction can be as low as 1.5 Ω.cm2 by using the optimized p-a-Si:H recombination layer.We obtain tandem solar cells with open circuit voltage Voc = 1.4 V,which is nearly the sum of the Vocs of the two corresponding single cells,indicating no Voc losses at the tunnel recombination junction.