Studies Of Alu Inum-boron-codoped Back Surface Field Of Crystalline Silicon Solar Cells And The Photovoltaic Properties Of Dye-sensitized Solar Cells Containing Submicro-sized Luminescent Particles

It has become one of the main means of improving cell efficiency by improving the surface passivation quality and reducing surface recombination velocity. Aluminum back surface field (AI-BSF) is widely used back surface passivated structure of crystalline silicon solar cells. It has good ohmic contact with basement and small surface recombination velocity. For back-passivated crystalline silicon solar cells, the local back surface field can further reduce surface recombination and reduce wafer warpage. In order to reduce the cost of solar cells, dye-sensitized solar cells has become a new hot research point. Photoelectric conversion efficiency of dye-sensitized cells is lower than crystalline silicon cells. In order to improve the conversion efficiency of the dye-sensitized solar cells, we added submicro-sized luminescent particles to the anode to improve optical properties. In this paper, we study the following aspects:Firstly, aluminum films and aluminum-boron films were prepared on silicon by magnetron sputtering. BSF was formed by rapid thermal annealing at different times and different temperatures. The morphology, electrical properties and doping concentration of Al-BSF and Al/B-BSF was studied. Secondary Ion Mass Spectrometry (SIMS) results showed that under the silicon back surface of2μm,the concentration of boron was1.2×1019atoms/cm3while that of aluminum atom was2.0×1018atoms/cm3. The sheet resistance of Al/B-BSF was significantly lower than that of Al-BSF. The results showed that the doped boron does decrease the sheet resistance.Secondly, the silicon was passivated by SiO2/SiNx:H double-films. After that Al+B (1%) film was sputtered by magnetron sputtering. Local aluminum back surface field was formed as1064nm Nd:YAG pulsed laser line scanning on the Al film. The effect of different current on preparing local aluminum back surface field was systematically studid. It was exhibited that10.5A current is the optimal choice to make flat back surface.Finally, submicro-sized luminescent particles YVO4:Eu3+,Bi3+(Eu3+5atm%,Bi3+5atm%)were prepared using a hydrothermal method, and the YVO4:Eu3+,Bi3+@SiO2core-shell particles were fabricated by a sol-gel method. These particles were embedded in the photoanodes of dye-sensitized solar cells. The embedded YVO4:Eu3+、Bi3+@SiO2particles not only enhanced light scattering within the photoanode. but were also able to down convert ultraviolet light to visible light. The enhanced light scattering can greatly extend the light traveling distance within the photoanode. while the ultraviolet-visible downconversion property can effectively improve the utilization of short wavelength photons by the dye-sensitized solar cells. The embedded submicron-sized YVO4:Eu3+,Bi3+@SiO2particles increased the power conversion efficiency of DSSC from3.6%to5.9%, about64%improvement.