I get vacuum UV photoluminescence specktums of rare earth doped inorganic compounds. when I check the literature to determine luminescence transitions, I came across emission spectras and excitation spectras. As an chemist, discrimination of these spectras is very hard study for me. Could someone explain this trouble?
Hello Gülşah,
Some inorganic compounds do not emit light after absorption of radiation therefore molecules do not have an excitation spectrum. Usually the absorbed energy can scatter in the molecule without emitting light. Moreover, the molecules absorb light at different excited states. The emission usually occurs from the lowest of these excited states known as S1. During the excitation to a higher state from ground state (S0) it often ends up in the lowest excited state S1 and then emits radiation. In such case the excitation spectrum is same as the absorption spectrum. Nevertheless from a higher excited state a molecule does not have to undergo to the lowest excited state but directly reaches the ground state in that case it does not emit radiation.
Hope that explains your question.
- Badges
- Science topic