PhotoSil UMG Silicon: Industrial Evaluation by Multi-c p-Type Ingots and Solar Cells

Abstract

In order to have a market perspective as UMG Silicon for the PV industry, PHOTOSIL Silicon needs to meet quality criteria in terms of PV cell and module performance as well as production cost objectives. To address these points a 2 generation industrial refining equipment has been made operational, with a total annual capacity of 100 MT, allowing for an industrial evaluation and qualification of PHOTOSIL Silicon. Results of two external evaluation tests of PHOTOSIL feedstock are presented in this article: (i) Using an industrial pilot line from Multi-c Silicon ingots to solar cells and (ii) by an industrial PV producer using state of the art multi-c ingot, wafering and cell processing equipment. In all cases 100% PHOTOSIL Silicon was used as feedstock for the ingot crystallization. The average cells efficiency obtained by these two routes is superior to 16% and the homogeneous material quality both on ingot and wafers is comparable to using Polysilicon as feedstock. The feedback of the industrial customer was positive, and 5 tons of PHOTOSIL Silicon has been ordered. All critical aspects regarding UMG Silicon have been carefully investigated and taken under control, like risk of SiC, SiN inclusions, resistivity control, etc. For a final validation of the quality of PHOTOSIL Silicon, modules have been made from multi-c Si PHOTOSIL Silicon and a total capacity of 100kWp has been installed in southern France in 2012 for monitoring and power rating. The energy production has been compared to standard modules with the same efficiency; the difference of energy production over a whole year is below 2%. Under high irradiation, the performance of both module types is similar, but under low irradiation the performance of the PHOTOSIL modules is 5% lower. No specific degradation has been observed, which confirms the potential for an industrial PHOTOSIL silicon production.