Solid State Solar Cell that Overcomes Limitations of Gratzel Cell

NU 2011-088 and NU 2011-092

Inventors

Robert Chang*

In Chung

Mercouri Kanatzidis*

Konstantinos Stoumpos

Byunghong Lee

Abstract

Northwestern researchers have developed a new solar cell that minimizes the limitations of conventional and current solar cells. This invention, the product of an interdisciplinary collaboration between a chemist and a nanotechnology expert, has a number of benefits, including lowering production cost, decreasing battery efficiency, and increasing its durability. In particular, their device solves a significant problem of the Grv§tzel cell, which was previously considered the promising future of solar cells because it was both cost-efficient and environmentally friendly. However, the Grv§tzel cell's electrolyte was made of organic liquid which was found to leak and corrode the solar cell itself. Further, these cells did not last more than 18 months. Northwestern researchers created a new electrolyte material for the Grv§tzel cell which starts as a liquid but then solidifies, producing a solid-state solar cell that is inherently more stable. This cell exhibits high conversion efficiency of approximately 10.2%. Unlike the Gratzel cell, it also utilizes both n-type and p-type semiconductors and a monolayer dye molecule serving as the junction between the two. The nanoparticles provide an enormous surface area upon which the light-absorbing dye is coated. The sunlight-absorbing dye sits between the semiconductors and is capable of absorbing more light over a wider range of the visible spectrum than the typical dye. This lightweight thin-film structure offers a more promising future in solar technology.

Applications