Global Warming Solar Cell

1. Solar Cell (Photovoltaics) 발표자 : 20075418 Ju Dae-Hyun Solar Cell (PV) Light Electricity

2. Nonrenewable Enargy 재생에너지원 (Renewable Energy) 일회용에너지원 (Nonrenewable Energy) Renewable

7. Actual Growth vs. Historic Forecasts Actual market development

9. - Gross revenue development 159 435 857 1705 2454 0 200 400 600 800 1000 1200 1400 1600 1800 2001 2002 2003 2004 2005 (MNOK)

11. Solar Grade Silicon Supply-Demand (MT/year)

14. Public incentives are important

15. Cost goals for third generation solar cells Efficiency and cost projections for first-, second- and third generation photovoltaic technology (wafers, thin-films, and advanced thin-films, respectively) Source: University of New South Wales

18. Understanding cell efficiency

21. The PV Value Chain (multi-crystalline) Polysilicon Wafer Solar Cell Solar Module Chemical Process (purification) Casting Cutting Surface Treatment Assembly Systems Installation Operation

22. Prices are actually increasing

23. How does solar energy work? Solar Electric or Photovoltaic Systems convert some of the energy in sunlight directly into electricity. Photovoltaic (PV) cells are made primarily of silicon, the second most abundant element in the earth's crust, and the same semiconductor material used for computers. When the silicon is combined with one or more other materials, it exhibits unique electrical properties in the presence of sunlight. Electrons are excited by the light and move through the silicon. This is known as the photovoltaic effect and results in direct current (DC) electricity. PV modules have no moving parts, are virtually maintenance-free, and have a working life of 20 - 30 years . Silicon Solar cell

24. Photovoltaics Most current solar cells are photovoltaic Typically made from silicon or amorphous silicon. Typical efficiency ~ 12%. Best efficiency ever in laboratory: ~30%. Theoretical maximum, including concentrating light: 43% Generic design: doped pn junction. Photons come in and photoionize donors. Built-in electric field at junction causes carriers to flow, building up a potential (voltage) btw the p and n sides. Clearly one can play with different band gap systems to arrive at materials with different absorption spectra. Also, good mobility of charge essential for this to work well - trapping of charge or poor mobility will kill efficiency.

25. Principle p-n Junction Diode. Silicon Solar cell Ref. Soft Condensed Matter physics group in univ. of Queenland

28. Poly-Si Solar cell Making process 기판준비 : Si ingot  330  m  2cm x 2cm Surface cleaning Texturing : chemical v-groove p-n junction : POCl 3 (900 ºC ) ITO increasing minorty carrier correction, ARC

29. Back Surface Field Deposition Al and Ag ohmic-contact Forward surface Electrode Anti-reflection coating (ARC) TiO 2 deposition

30. H 2 diffusion dangling bond H2 bonding  Decreasing recombination Measure H 2 H 2 H 2 H 2

31. - An individual PV cell typically produces between 1 and 2 watts Solar Cell, Module, Array

34. Uses for Solar Energy

35. Main Application Areas – Off-grid Solar Home Systems Space Water Pumping Telecom

36. Main Application Areas Grid Connected Residential Home Systems (2-8 kW) PV Power Plants ( > 100 kW) Commercial Building Systems (50 kW)