Properties of boron-rich layer formed by boron diffusion in n-type silicon

A boron-rich layer (BRL) is formed during the boron diffusion process in fabricating crystalline Si solar cells. We investigated the structural, optical, and electrical characteristics of BRL in n-type silicon. A boron emitter was formed using the BBr3 liquid source in a tube furnace at 950 °C. BRL had an amorphous phase. The peak concentration of boron in BRL was over 1023 atoms/cm3. BRL consisted of boron, silicon, and oxygen. The oxygen atoms seemed to have caused the formation of amorphous phase. BRL showed the refractive indices of 1.5-2.0, and the contact resistance of 0.8 mΩ cm2.