고온소결형 태양전지용 silver paste의 레오로지 특성 및 성능평가

Abstract

A study on Silver paste for solar cell performance evaluation and rheological measurements

Jung-Woo Cho

Department of Graphic Arts Engineering, Graduate School, Pukyong National University

Abstract

The sun is a limitless and clean source of power. The energy the earth's surface receives from the sun in one hour is equivalent to the world's annual energy consumption and almost none of the greenhouse gas associated with fossil fuels is produced from solar power. Solar power generation is the technique of obtaining electricity directly from sunlight, at the core of which lie solar cells, which convert sunlight directly into electricity. Early solar cells were used to generate power on spacecraft and their application to regular power generation began to receive attention after the oil shocks of the 1970s. As energy and environmental issues become global problems, solar cells have come to be considered as one of the most viable renewable energy technologies. Solar cell production has increased by more than 40 percent each year for the past five years and in 2007 more than 4 gigawatts worth were produced and production is projected to reach 20 gigawatts worth in 2010. If the current growth rate is maintained, electricity from photovoltaics (PV) will be able to supply 10 percent of the world's total electricity needs. At present, first generation solar cells - those made from crystalline silicon - account for about 90 percent of the market. However, problems with silicon supplies and conversion efficiency and the high production cost have prevented solar cells from being economically competitive and hampered the growth of the solar power industry. So, in order to overcome the limitations of the first generation solar cells and produce them more cheaply, research organizations and companies all over the world are trying to develop next generation of solar cells through technologies like amorphous silicone, GaAs, CIGS, CdTe, spherical silicone solar cell. Spherical silicone solar cells are produced from silicon ball and aluminium sheets. Since they are more inexpensive than crystalline silicon wafers and they can be produced using only about 20 percent of the materials required for crystalline silicon wafer production. As such, the production cost is expected to be dramatically lower with Spherical silicone solar cells. This study shows a method manufacturing a front electrode for spherical silicone solar cell by the screen print method and contents that the physical properties examined. Flake type, Spherical type, Aggregation type's Ag powder was used as a conductivity filler and made comparitive pastes on Ethyl Cellulose resins as an organic binder to give adhesive strength on substrate. The purpose of this study is to know the effects of the conductivity filler on Ag paste including dispersibility, conductivity and adhesive property and a special quality of the solar cell including Jsc, Fill factor, Voc, Rseise and Efficiency.