Silicon Alley build a US$2 billion graduate school of applied sciences on Roosevelt Island, with the goal of transforming New York City into the world's premier technology capital. As of 2013, Google's second largest office is located in New York. Verizon Communications, headquartered at 140 West Street in Lower Manhattan, was in 2014 in the final stages of completing a US$3 billion fiberoptic telecommunications upgrade throughout New York City. This revival was not restricted to Lower Manhattan, but was spread throughout New York City. Hence "Silicon Alley" has been considered by some observers to be an obsolete term. Silicon Alley Silicon Alley,
Polycrystalline silicon grain boundaries, see figure 1. The resistivity, mobility, and free-carrier concentration in monocrystalline silicon vary with doping concentration of the single crystal silicon. Whereas the doping of polycrystalline silicon does have an effect on the resistivity, mobility, and free-carrier concentration, these properties strongly depend on the polycrystalline grain size, which is a physical parameter that the material scientist can manipulate. Through the methods of crystallization to form polycrystalline silicon, an engineer can control the size of the polycrystalline grains which will vary the physical properties of the material. The use of polycrystalline silicon in the production of solar cells requires