In the context of semiconductors, such as silicon, the term "hole" refers to the absence of an electron in the valence band of an atom. When an electron in the valence band moves to a higher energy level (conduction band), it leaves behind a hole.
In photovoltaic (solar) cells, which are made of semiconducting materials like silicon, the interaction with photons from the sun can indeed generate electron-hole pairs. When a photon with sufficient energy is absorbed by the semiconductor material, it can excite an electron from the valence band to the conduction band, creating an electron-hole pair.
The generated electron and hole can then move independently through the material. In the case of a solar cell, there are usually built-in electric fields within the semiconductor material that help separate the electron-hole pairs and guide them towards the respective electrodes. This separation of charges creates a potential difference, allowing the flow of electrons as an electric current.
However, it's important to note that photons do not "fill" the existing holes in a literal sense. The process involves the absorption of photons, which leads to the creation of electron-hole pairs. The energy from the photons is transferred to the electrons, promoting them to higher energy states and creating the free charge carriers.
In summary, photons from the sun can indeed generate electron-hole pairs in a semiconductor material like silicon, which is the basis for the operation of solar cells.