The ultra-small textured surface of multicrystalline silicon solar cell,prepared by electroless chemical-etching method,shows an excellent anti-reflection property over a wide spectral bandwidth.A novel back surface protection method and front surface passivation method have been used in the multicrystalline solar cells with ultra-small textured surfaces.With these improvements,the back surface remains intact after the etch process and the efficient minority lifetime is apparently increased.The test result shows that the solar cell with ultra-small textured surface can obtain better electrical performances by these improvements.
Silicon solar cells are prepared following the conventional fabrication processes, except for the metal- lization firing process. The cells are divided into two groups with higher and lower fill factors, respectively. After light-induced plating （LIP）, the fill factors of the solar cells in both groups with different initial values reach the same level. Scanning electron microscope （SEM） images are taken under the bulk silver electrodes, which prove that the improvement for cells with a poor factor after LIP should benefit from sufficient exploitation of the high density silver crystals formed during the firing process. Moreover, the application of LIP to cells with poor electrode contact performance, such as nanowire cells and radial junction solar cells, is proposed.
Nanostructure-textured solar cell owns unique properties but has some shortages especially in its fabrication and passivation.In this paper,nanostructures for crystalline silicon solar cell have been synthesized by controllable method based on silver catalyzed chemical etching.In this way,only the front surface of cell is etched and rear surface is protected.It was found that cells textured via the new method obtained equally excellent optical while superior electrical properties compared with those textured via traditional HF/AgNO3 etching.The V OC and I SC of the cell were improved by 6% and 11%,respectively.Then the cells were passivated via a bi-layer passivation(SiO2 & SiN x),in contrast to traditional SiN x passivation.It was also found that cells with new passivation exhibited improved V OC and I SC by 4% and 25%,respectively.The encouraging results can provide fundamental data for developing the nanostructure-textured crystalline silicon solar cell in following researches.
