Solar panels have long been touted as an energy solution - whether it is solar panels fitted on to homes, or solar powered cars. However, their lack of efficiency and comparatively high prices has prohibited them from breaking into the mainstream.
Now however, there is a new solution for solar panels. Previously the panels were made predominantly from silicon - and the high demand for silicon in turn led to high prices. However, now Gang Chen from Cambridge University has proposed a new solution - in the form of nanowire solar cells.
Here is where it gets technical! The nanowire solar cells consist of arrays of radical p-n junction nanowires. The darker outer cells are composed of n-type silicon to which phosphorous has been added, while the lighter inner cell uses p-type silicon to which the electron donor boron is added. The result is that each individual nanowire is capable of acting as a photovoltaic cell.
As these do not reflect light in the way current solar cells do, they offer much greater efficiency. The absorption rate is high and the wavelength of light is boosted. Therefore there’s no need for expensive anti-reflective coatings.
What still remains to be determined is the efficiency of photon capture in the nanowire structures. However, the nature of this material allows for lower quality silicon to be used and should significantly lower the price of solar panels.
