This research develops high open-circuit voltage (V OC ) p-type industrial screen-printed silicon solar cells using improved rear surface passivation. It shows a significant improvement in the minority carrier lifetime by low temperature (<450°C) thermal atomic layer deposition of Al 2 O 3 layers and plasma-enhanced chemical vapor deposition of SiN x passivation layers. An increase in the V OC and the short-circuit current ( J SC ) due to an improved long-wavelength response are also demonstrated. With the optimized stack layers, a high efficiency of 19.2% across a large area (156 cm 2 ) is seen. Furthermore, the rear-side passivation scheme can be easily integrated into the conventional screen-printed process. This is very promising for in-line solar cell manufacturing. Index Terms-Al 2 O 3 /SiN x stack layers, negative fixed charge, open-circuit voltage, surface passivation.

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In this article, an expression for the surface passivation has been derived in terms of the surface recombination velocity and the field-effect exponential. The analytical solutions provide a comprehensive understanding of the injection dependency of minority charge carrier lifetime as measured by photoconductance decay. The model has been utilized to analyze the field-effect passivation of silicon exerted by the fixed dielectric charge in an overlying dielectric film. Possible limitations and restrictions of the technique are also addressed.

Oil spills have always been a threat to the marine ecological environment; thus, it is important to identify and divide oil spill areas on the ocean surface into segments after an oil spill accident occurs to protect the marine ecological environment. However, oil spill area segmentation using ordinary optical images is greatly interfered with by the absorption of light by the deep sea and the distribution of algal organisms on the ocean surface, and it is difficult to improve segmentation accuracy. To address the above problems, a hyperspectral ocean oil spill image segmentation model with multiscale feature fusion (MFFHOSS-Net) is proposed. Specifically, the oil spill segmentation dataset was created using hyperspectral image data from NASA for the Gulf of Mexico oil spill, small-size images after the waveband filtering of the hyperspectral images were generated and the oil spill images were annotated. The model makes full use of having different layers with different characteristics by fusing feature maps of different scales. In addition, an attention mechanism was used to effectively fuse these features to improve the oil spill region segmentation accuracy. A case study, ablation experiments and model evaluation were also carried out in this work. Compared with other models, our proposed method achieved good results according to various evaluation metrics.

Plasma deposition of intrinsic microcrystalline silicon films is a key process for the fabrication of high efficient silicon thin-film solar cells. The process results are extremely determined by the plasma properties. Recent studies have shown that the concentration of the radical species in hydrogen diluted silane plasma is time-dependent during the deposition process and results in inhomogeneous film growth. 1-2 The major reason of process drift is believed to be as a result of the change of chamber wall surface condition. In this study, trace rare gases-optical emission spectroscopy (TRG-OES) 3 was used to determine the absolute species concentrations (e.q. Si, SiH x , H) by deriving from their optical emissions signals, as well as the temporal variation of electron temperature during the deposition process. The experimental results show that the OES intensities have obvious spikes after plasma is ignited and then decreases to a lower level at the first stage in about 10 seconds. This is because of the pressure unbalance between the throttle valve control and the expanded number density of gas induced by plasma heating and dissociation reaction in the chamber. After the transient of pressure unbalance, the intensity of H α increases close to 20 % and the SiH * decreases 10 % during the deposition in 10 minutes. The growth structure and crystallinity of deposited microcrystalline silicon films will also be presented.