Effect of the CO₂/SiH₄Ratio in the p-μc-SiO:H Emitter Layer on the Performance of Crystalline Silicon Heterojunction Solar Cells

Abstract

This paper reports the preparation of wide gap p-type hydrogenated microcrystalline silicon oxide (p-μc-SiO:H) films using a 40 MHz very high frequency plasma enhanced chemical vapor deposition technique. The reported work focused on the effects of the CO2/SiH4ratio on the properties of p-μc-SiO:H films and the effectiveness of the films as an emitter layer of crystalline silicon heterojunction (c-Si-HJ) solar cells. A p-μc-SiO:H film with a wide optical band gap (E04), 2.1 eV, can be obtained by increasing the CO2/SiH4ratio; however, the tradeoff betweenE04and dark conductivity must be considered. The CO2/SiH4ratio of the p-μc-SiO:H emitter layer also significantly affects the performance of the solar cells. Compared to the cell using p-μc-Si:H (CO2/SiH4= 0), the cell with the p-μc-SiO:H emitter layer performs more efficiently. We have achieved the highest efficiency of 18.3% with an open-circuit voltage (Voc) of 692 mV from the cell using the p-μc-SiO:H layer. The enhancement in theVocand the efficiency of the solar cells verified the potential of the p-μc-SiO:H films for use as the emitter layer in c-Si-HJ solar cells.

Nano-composite microstructure model for the classification of hydrogenated nanocrystalline silicon oxide thin films

“…Thus, it has been researched extensively, especially for the application in silicon solar cells, e.g. as doped layers in silicon heterojunction solar cells [1][2][3][4] and wide gap window layers or intermediate reflectors in multijunction thin-film solar cells [5][6][7]. The excellent properties of nc-SiO X :H films stem from their unique microstructure.…”