AbstractThe improvement of optical confinement on the back crystalline silicon solar cell is one of the factors leading to its better performance. Porous silicon (PS) layer can be used as a back reflector (BR) in solar cells. In this work, single layers of porous silicon were grown by electrodeposition on a single crystalline silicon substrate. The measurement of the total reflectivity (RT) on Si/PS surface showed a significant improvement in optical confinement compared to that measured on Si/standard Al back surface field (BSF). The internal reflectivity (RB) extracted from total reflectivity measurements achieved 86 % for the optimized single PS layer (92 nm thick layer with 60 % porosity) in the wavelength range between 950 and 1200 nm. This improvement was estimated as more than 17 % compared to that measured on the surface of Si/BSF Al contact. To improve the stability and passivation properties of PS layer BR, silicon nitride layer (SiNx) was deposited by PECVD on a PS layer. The maximum measured total reflectivity for PS/SiNx achieved approximately 56 % corresponding to an improved RBof up to 83 %. The PS formation process in combination with the PECVD SiNx, can be applied in the photovoltaic cell technology and offer a promising technique to produce high-efficiency and low-cost c-Si solar cells.
High Efficiency, Low Cost Solar Cells Manufactured Using 'Silicon Ink' on Thin Crystalline Silicon Wafers
