High-efficiency screen-printed planar solar cells on single crystalline silicon materials

In this paper we report on the fabrication, characterization and analysis of high efficiency planar screen-printed solar cells with high sheet resistance emitter ∼ 100 Ω/square. Three single crystalline materials were used in this study including; boron doped magnetically stabilized Cz (MCz), gallium-doped Cz (GaCz) and float zone (FZ). For these three materials, a wide range of resistivities was investigated including Fz -0.6-4.1 Ω-cm, MCz 1.2-5.3 Ω-cm and Ga-Cz 2.6-33 Ω-cm. Energy conversion efficiencies of 17.7% were achieved on both Fz (0.6-Ω-cm) and MCz (1.2-Ω-cm) while 16.9% was obtained on GaCz silicon material. The 17.7% efficiency achieved on these two materials is the highest energy conversion efficiency reported on a planar screen-printed silicon solar cell. These results demonstrate the importance of high sheet resistance emitter in achieving high efficiency manufacturable solar cells.