Patent ID: 8283559

Claim:
A solar cell, comprising: a metallurgical-grade Si (MG-Si) substrate; a first heavily doped crystalline-Si layer situated above the MG-Si substrate; a lightly doped crystalline-Si layer situated above the first heavily doped crystalline-Si layer; a second heavily doped crystalline-Si layer situated above the lightly doped crystalline-Si layer; front electrodes situated above the second heavily doped crystalline-Si layer; a passivation layer situated between the second heavily doped crystalline-Si layer and the front electrodes, wherein the passivation layer passivates a surface of the second heavily doped crystalline-Si layer, wherein the passivation layer includes a three-layer dielectric stack, wherein the three-layer dielectric stack includes a SiO x N y layer in contact with the second heavily doped crystalline-Si layer, a hydrogenated SiN x layer in contact with the front electrodes, and a oxide layer situated between the SiO x N y layer and the hydrogenated SiN x layer, and wherein the SiO x N y layer relaxes interfacial stress between the second heavily doped crystalline-Si layer and the oxide layer; and a backside ohmic-contact layer situated on the backside of the MG-Si substrate.