In a dye-sensitized solar cell, the energy level corresponding to the electron orbit of the dye molecule is a straight line, and the energy of the semiconductor electron opposite thereto is represented by an energy band (a rectangle in b). The dye molecule and the metal ion (Ru) are surrounded by a ligand composed of elements such as carbon (C), hydrogen (H), oxygen (0), and nitrogen (N) to form a complex structure. Here, the electron orbitals of the metal ions are mixed with the electron orbitals of the ligand ions to form a molecular orbital. These electron orbitals are confined within the molecule and cannot move outside the molecule, so the kinetic energy is small, and most of the energy levels are represented by narrow energy levels (straight lines). In the molecular orbital with electron filling, the highest energy state is called HOMO, and the lowest energy state in the empty molecular orbit is called

LUMO. If illuminated with light that excites molecular energy, the electrons will absorb energy and from HOMo

Jump to LUMO