Growth and Development of Sapphire Crystal for LED Applications

LEDs (Light emitting diodes) are considered as the most promising green lighting sources in 21st Century for the advantages in high brightness, long lifetime (more than 50,000 hours), low energy consumption, short corresponding time, good shock resistance, non-toxic, recy‐ clable, safety. LEDs have already been extensively used in outdoor displays, traffic lights, high-performance back light units in liquid-crystal displays, general lighting. Strategies Un‐ limited Company predicted that the compound annual growth rate (CAGR) of the LED mar‐ ket would increase to 30.6%, up to $20.2 billion in 2014. It is obvious that incandescent bulbs and fluorescent lamps will be replaced by LEDs, which could alleviate the increasingly seri‐ ous global energy crisis. Therefore, the development of semiconductor lighting industry is of great significance. Many countries have already launched National Semiconductor Light‐ ing Plan, investing heavily in researching and developing the LEDs industry. In 1998, Japan made a “Light for the 21st Century” plan with the budget of 6 billion yen. In July 2000, Eu‐ ropean Union implemented “Rainbow project bring color to LEDs” plan, setting up ECCR and promoting the application of white light LED through the EU BRITE/ EURAM-3 pro‐ gram. U.S. Department of Energy established “National research program on semiconductor lighting” plan. It is expected that in 2025, the use of solid state lighting will reduce half of the lighting electricity consumption and save $35 billion per year. In June 2003, the Chinese Ministry of Science and Technology launched an “National Semiconductor Lighting Project” in support of the “863” Project. In 2009, ministry of Science and Technology started “Ten thousand LED lights in ten cities” semiconductor lighting demonstration program. It is ex‐ pected that in 2015, semiconductor lighting will occupy 30% of the domestic general lighting market.