Use of gas jet deposition technique to prepare a-Si:H solar cells

We have tested the feasibility of using a new gas jet deposition technique to deposit hydrogenated amorphous silicon (a-Si:H) i-layers for solar cells at high deposition rates. With this technique, a source gas flow is forced at high speeds through a jet nozzle pointed at the heated substrate surface. Before reaching the substrate surface, the gas is activated by an electron beam which produces radicals which deposit on the substrate surface forming the thin film. We have prepared single-junction a-Si:H n-i-p cells with 9.4% and 8.7% efficiencies at i-layer deposition rates of 2 Å/s and 5 Å/s, respectively. Initial light soaking results suggest that these cells are as stable as those having the same i-layer thickness prepared using the PECVD technique. We plan to further develop this new deposition technique to demonstrate that a-Si:H and a-SiGe:H cells can be prepared at faster deposition rates with even higher stable efficiencies