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Shining Light on Solar Cells - Chapter 9.0: Multi-junction (Tandem) Solar Cells

Multi-junction/tandem solar cells are created in an effort to surpass the Shockley Queisser Limit. You can learn more about this limit in Chapter 5.1. Instead of one layer of pn junction, multijunction solar cells employ two junctions. The top junction is a high bandgap solar cell to absorb high-energy photons, while the bottom junction is a low-bandgap solar cell to absorb low-energy photons. This way, we get more voltage from solar cells, eventually leading to possibilities of surpassing the Shockley Queisser Limit.

Multijunction (tandem) solar cells. (Image credit: PV Education)

Image from PV Education

While the concept of multi-junction solar cells is easy to understand, the actual design is more complex than that. In this video, let us explore two design areas in multijunction solar cells: lattice-matching and current-matching. Enjoy the video!

Other parts in this series:

Further reference materials that I highly recommend:

Luque, A. and Hegedus, S. (2003). Handbook of Photovoltaic Science and Engineering. John Wiley & Sons. ISBN: 978-0-471-49196-5.

I'm an R&D Mechanical Engineer from Keysight Technologies. I design mechanical components that facilitate over-the-air testing equipment. I also have a strong background in photovoltaics. I love creating STEM-related content to inspire and encourage people to pursue STEM, as well as to provide career advice to fresh grads who are looking for their first job