As discussed in our earlier post (Materials Engineering: A practical solution for energy crisis), replacement of fossil fuel energy sources with renewable (green) ones is essential in order to keep the energy price and pollution low. Solar cells are the primarily and widely used alternative for the conventional energy sources. However, the fabrication of silicon wafers is rather costly and hence the solar power prize is still high. Thinning of the solar panels corresponds to less materials consumption and ultimately cheaper prize. In other words, major cost of solar panels is owing to the expenses of silicon materials and processing.
Thin film solar cells with thickness generally below 2µm are the solution to the aforementioned problems. Copper-Indium-Gallium-Selenide (CIGS) solar cell is one of the widely studied and developed thin film cells with efficiency up to 20%. Due to the low production cots (co-evaporation), less materials consumption, flexibility and performance comparable to that of Si-based solar panels, their industrial usage in market is growing. Nevertheless, thin films based on amorphous silicon are the major competitor of CIGS and having higher share of the market. Indeed, complexity of the control of the composition of the absorbing layer of CIGS cells, which dictate the performance, is still a one of the challenge ahead of this industry.
Although there is a considerable efforts to leverage the performance of the thin film solar cells, conventional silicon solar panels are the major option for energy harvesting purposes. Further innovative designs, smart materials selection and cheaper fabrication methods are still needed to be developed in order to push thin film solar cells as an alternative to the conventional silicon solar panels.