Yuko Fukawa

Surface and bulk-passivated large area multicrystalline silicon solar cells

Abstract We have investigated the surface and bulk passivation technique on large-area multicrystalline silicon solar cells, a large open-circuit voltage has been obtained for cells oxidized to passivate the surface and hydrogen annealed after deposition of silicon nitride film on both surfaces by plasma CVD method (PSiN) to passivate the bulk. The texture surface like pyramid structure on multicrystalline silicon surface has been obtained uniformly using reactive ion etching (RIE) method. Combining these RIE method and passivation schemes, the conversion efficiency of 17.1% is obtained on 15 cm × 15 cm multicrystalline silicon solar cell. Phosphorus diffusion, BSF formation, passivation technique and contact metallization for low-cost process sequence are also described in this paper.

Large-area high efficiency single crystalline silicon solar cells

Abstract This paper reports on a 100 cm 2 single crystalline silicon solar cell with a conversion efficiency of 19.44% ( J sc = 37.65 mA/cm 2 , V oc = 638 mV, FF = 0.809). The cell structure is as simple as only applying the textured surface, oxide passivation, and back surface field by the screen printing method. The comparison between cell performances of the CZ (Czochralski) and FZ (Floating zone) silicon substrates was investigated. The higher efficiency cells were obtained for the FZ substrate rather than the CZ substrate. The influence of the phosphorus concentration of the emitter on the cell efficiency has also been investigated. A good result was obtained when the surface concentration of phosphorus was 3 × 10 20 cm −3 and the junction depth was about 0.6 μm.