OPTIMIZATION OF CONTACT HOLE FORMATION PROCESS BY REACTIVE ION ETCHING FOR CUBIC SILICON CARBIDE/SILICON HETEROJUNCTION SOLAR CELLS WITH HYDROGENATED AMOURPHOUS ALUMINUM OXIDE REAR SURFACE PASSIVATION LAYER

摘要

Amorphous aluminum oxide (a-Al_(1-x)O_x:H) is one of the promising materials for the rear surface passivation layer of crystalline silicon (c-Si) solar cells. a-Al_(1-x)O_x:H films with good passivation quality for p-type c-Si were deposited by plasma enhance chemical vapor deposition (PECVD). We employed a reactive ion etching (RIE) technique to make contact holes for a-Al_(1-x)O_x:H passivation layer and optimized RIE conditions and thermal annealing conditions after metal evaporation. Under the optimum condition, good ohmic contact with low contact resistance was realized. A good fill factor of 0.795 was obtained for n-type nanocrystalline cubic silicon carbide/p-type c-Si heterojunction solar cells with the RIE contact process.