Slimming down solar cells

The activity tested a method where the surface of the Germanium substrate is treated so that a cavity is introduced just below it. Once a solar cell is grown on the Ge surface, this 0.001 mm thick gap, or cavity, allows everything above it to be removed, leaving just a very thin layer of germanium still attached to the cell - around 10 micrometres thick instead of the previous 150.

This huge saving of weight and volume of a rare material will result in major cost savings, especially when multiplied across the roughly 10 000 solar cells needed for each satellite mission.

For more than a quarter of a century ESA's optional GSTP has been preparing promising technologies for space and the open market. Read our GSTP Annual Report for 2019 to learn more about programme activities.