Wide Gap Microcrystalline Silicon Oxide Emitter for a-SiOx:H/c-Si Heterojunction Solar Cells

This paper reports on the development of phosphorous doped microcrystalline silicon oxide (µc-SiOx:H) films as an emitter window layer in flat p-type silicon heterojunction (SHJ) solar cells featuring intrinsic a-SiOx:H buffer layers. We investigated the material properties of n-type µc-SiOx:H films grown at various input gas ratios and correlated the results of SHJ solar cells utilizing varying oxygen content and thickness of the emitter layer to the corresponding film properties. A maximum efficiency of 19.0% was achieved. The excellent short circuit current of 35.8 mA/cm2for flat cells was attributed to the low optical losses in the emitter window.