When radiation hits quartz, it excites electrons. electrons jump from the valence band (low energy) to the conduction band (high energy). This leaves behind holes in the valence band. The free electrons and holes can then move through the crystal.
If a defect (like an oxygen vacancy or an iron impurity) is present, it creates localized energy levels inside the wide bandgap. These levels can trap electrons or holes. The electron is trapped at an energy level lower than the conduction band.
Quartz is used in luminescence dating and ESR (Electron Spin Resonance) dosimetry, methods that measure radiation doses or date archaeological/geological samples. These applications depend on defects in the quartz lattice, which act as traps for charge carriers (electrons and holes) after exposure to radiation.
It is found that peroxy defects( two oxygen atoms bond directly to each other) can be formed in the presence of either excess Oxygen or due to the absence of Silicon (Si4+).
Oxygen vacancies and oxygen interstitials (excess oxygen) create trap states -they are responsible for electron and hole trapping, important for luminescence and ESR.
Passivated oxygen vacancies (with H or OH) do not create trap states- they neutralize defects.
https://arxiv.org/pdf/2504.18077
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