Novel spin coated phosphorus sources for gettering process on crystalline silicon

Three different novel liquid phosphorus dopant sources, based on a combination of phosphoric acid (H3PO4) and phosphorus pentoxide (P2O5), were spin-coated onto p-type crystalline silicon wafers. Heat treatment under an ambient atmosphere has been carried out at 925 o C for 30 min in order allowing P diffusion into the wafers. Photoconductance measurements quantified the improvement in the quality of silicon using either bulk effective minority carrier lifetime (τeff) or implied open circuit voltage (iVoc) parameter; e.g. τeff of single crystalline silicon raised up to around 760 μs where initial value was around 330 μs and iVoc of multi crystalline silicon solar cells was increased from 598 mV up to 625 mV. These primary results on newly introduced spin coated dopant sources come along with effective diffusivity by taking advantage of both H3PO4 and P2O5 and can be a promising low-cost alternative improving wafer level quality for the silicon solar cell technology.