What is the function of the semiconductor crystal within a semiconductor detector?

The function of the semiconductor crystal within a semiconductor detector is to convert X-rays into electrons. This process is fundamental for the operation of semiconductor detectors, as they are designed to detect high-energy radiation such as X-rays and gamma rays.

When X-rays interact with the semiconductor material, they transfer their energy to the electrons in the crystal lattice, allowing these electrons to escape from the bound state, which generates electron-hole pairs. The movement of these charge carriers can be collected, resulting in a measurable electrical signal proportional to the incident radiation's energy. This capability enables the semiconductor detector to provide precise measurements of the radiation intensity, which is critical in various applications, including medical imaging and radiation safety.

The other options describe processes that do not pertain to the function of a semiconductor crystal in this context. For instance, converting light into chemical energy is more relevant to photosynthesis or photochemical processes, while converting photons into visible light usually occurs in phosphorescent or fluorescent materials. Additionally, the conversion of neutrons into protons falls into nuclear reaction processes, which is not the operational principle of semiconductor detectors.