Hold a piece of hematite in each hand, close your eyes, and take three deep breaths. As you breathe, visualize yourself as a tall, strong tree. See the roots of the tree—a few inches in diameter—growing from the sole of each foot and spiraling down into the core of the Earth to create a solid foundation.
Hematite (Fe 2 O 3) is a common oxidization product on Earth, Mars, and some asteroids. Although oxidizing processes have been speculated to operate on the lunar surface and form ferric iron–bearing minerals, unambiguous detections of ferric minerals forming under highly reducing conditions on the Moon have remained elusive.
We revisit the fundamental constraints that apply to flat band potential values at semiconductor photo-electrodes. On the physical scale, the Fermi level energy of a non-degenerate semiconductor at the flat band condition, EF(FB), is constrained to a position between the conduction band, EC, and the valence