Papers by Keyword: Hydrogen Plasma Treatment

Abstract: We explain the experimental improvement in long wavelength response by hydrogen plasma treatment (HPT) in n/i interface. The absorption coefficient of the intrinsic microcrystalline silicon (μc-Si) is decreased in the low energy region (0.8~1.0 eV) by HPT, which indicates a lower defect density in μc-Si layer deposited with HPT than its counterpart without HPT. Simulation by one-dimensional device simulation program for the Analysis of Microelectronic and Photonic Structures (AMPS-1D) shows a higher long wavelength response in μc-Si solar cell if the defect density in intrinsic μc-Si layer is smaller. Our simulation results also disclose that the less defect density in intrinsic layer, the lower recombination rate and the higher electric field is. Higher electric field results in longer drift length which will promote collection of carriers generated by photons with long wavelength. Thus we deduce that HPT decreased defect density in absorber layer and improved the performance of μc-Si solar cells in long wavelength response.

Abstract: Properties of n-i interface are critical for hydrogenated microcrystalline silicon (μc-Si:H )substrate-type (n–i–p) solar cell as it affects carrier collection, which is visible in the red response . Here, we report a remarkable improvement in visible-infrared responses upon hydrogen plasma treatment （HPT）of n/i interface. We demonstrate that hydrogen plasma treatment in the initial stage of a μc-Si:H i layer growth affects the red response of μc-Si:H solar cell. At the optimal deposition condition, 18% higher short-circuit current density was obtained than its count part without using HPT

Abstract: It is necessary to improve the open circuit voltage of amorphous silicon solar cells for its applications. In this paper, we discuss the effects of hydrogen plasma treatment on the P layer and the performance of the amorphous silicon solar cells. The result shows that the open circuit voltage increased by 0.0257V, the fill factor increased by 0.039 and the energy conversion efficiency increased by 9%. The highest V_OC we got was 0.99V. Treating P layer with hydrogen plasma has been demonstrated to result in materials with improved crystalline volume fraction which was very effective to increase the light absorption of the intrinsic layer. What is more, it could be easily integrated into the amorphous silicon solar cell mass production process.

Abstract: In this work we studied the influence of the power density of hydrogen plasma on electrical and optical properties (Hall mobility, free carrier concentration, sheet resistance, optical transmittance and a.c. impedance) of indium zinc oxide films, aiming to determine their chemical stability. This is an important factor for the optimization of amorphous/nanocrystalline p-i-n hydrogenated silicon (a/nc-Si:H) solar cells, since they should remain chemically highly stable during the p layer deposition. To perform this work the transparent conductive oxide was exposed to hydrogen plasma at substrate temperature of 473 K, 87 Pa of pressure and 20 sccm of hydrogen flow. The results achieved show that IZO films were reduced for all plasma conditions used, which leads mainly to a decrease on films transmittance. For the lowest power density used in the first minute of plasma exposition the transmittance of the IZO films decreases about 29%.