Perovskite solar cells made simply

have you heard about the latest gadgets making waves and solar cell research they're called perovskite solar cells they're generating quite a buzz because they're quickly getting better and better at converting sunlight to electricity and because they can be made simply and inexpensively by using common wet chemistry lab methods in ordinary low-cost equipment instead of the expensive deposition equipment common in the semiconductor industry step inside labs at Notre Dame and northwestern universities to see some of the methods that make this process cheap and accessible every lab tweaks the procedure to suit its research focus but many of the steps are common to all researchers studying prof. skite cells these solar cells or photovoltaic cells are typically made in a layer by layer fashion on a specially coated glass support this particular lab first treats the coated glass with the dense layer of titanium dioxide to prevent electrical charge generated by sunlight from leaking out of the cell this robotic arm forms that layer by spraying a titanium dioxide solution onto the glass next a less dense porous oxide layer covers the dense oxide layer generally it's titanium dioxide but other oxides have been used as well a simple high-speed spin coater deposits this layer from solution and spreads it evenly across the device heating in an oven conditions it for solar cell use next up is the prof Skype material which absorbs an especially broad range of the solar spectrum to prepare the prof sky used in this lab these researchers combine two precursor materials lead iodide and methyl ammonium iodide they drip the liquid phase mixture onto the oxide coated device and give it a spin to spread the film uniformly now comes the color-coordinated fun part and all it takes is an ordinary lab hot plate gently heating the device after applying the halite solution spontaneously crystallizes the precursors in the freshly deposited liquid in this example they're forming methylammonium lead iodide which adopts the well-known profs kite crystal structure after which the solar cells are named it's easy to know when the precursors undergo crystallization the color change is pretty obvious after completing a few more steps the device is ready for testing hook it up turn on a solar simulator such as a laboratory xenon lamp and voila this little device transforms light energy to electricity you probably won't find props kite solar cells on rooftops at least not in large numbers anytime soon but judging from the recent explosion and research popularity these low-cost photovoltaic cells are likely to show up soon in a lab near you for chemical and engineering news a Mitch Jacoby

Channel: Chemical & Engineering News

Views: 99,025

Keywords: Perovskite, solar cells

Id: oQ2bz6jlbz0

Length: 2min 57sec (177 seconds)

Published: Wed Feb 26 2014