Era of affordable and efficient solar panels is not far away

          Efficiency of solar cell refers to the portion of energy in the form of sunlight that can be converted into electricity via photovoltaics by the solar cell. Silicon based solar cells, by far is the most common material in the residential solar market today. If a solar panel has 20% efficiency that means it’s capable of converting 20% of the sunlight hitting it into the electricity. The highest efficiency solar panels can reach almost 23% efficiency. But the average efficiency of solar panels falls between 15 to 18% efficiency range.

        The average efficiency of solar panels is lower than the maximum efficiency. But if you raise the overall efficiency, you don’t have to install as many panels to get the same amount of power.

What will improves efficiency is to put another solar cell on top of an existing one?

       Researchers took a PEROVSKITE SOLAR CELL, a crystal that’s designed to harvest photons of high energy. It is layered on the top of a silicon solar cell, which captures more photons in the infrared part of the spectrum. This layering increases the efficiency of 21% of silicon cell to an efficiency 27%. Researchers started fewer than 10 years ago with the concept using less expensive materials on top of the silicon, and at the first only achieved about 13% efficiency. But through improvements they have been able to improve this number.

      Researchers in it, used three main things- halide alloy of chlorine, bromine and iodine. There is a ideal band gap in the solar cells. Bromine can raise this bandgap but when iodine is used and exposed to light then these elements don’t stay in place. Using different amounts of bromine, chlorine and iodine, the researchers figured out a way to shrink the crystal structure and more chlorine to fit in perovskite and stabilise it.

Perovskites are inexpensive and easy to create in labs. This means that it now costs more to install the cells than to buy them.  With solar power market growing around 30% per year, efficiency, cost and longevity are major considerations. Researchers believe that it can take them to 30% efficiency soon and they are very optimistic about it.