Incandescence or thermoluminescence is the production of light from heat. ... Phosphorescence and fluorescence are the processes of converting invisible UV energy emitted normally from an electrical discharge into visible light. Material called phosphors cause UV energy to make this transition into visible light.

https://www.sciencedirect.com/topics/materials-science/thermoluminescence

Please see the attachment below:

Article Investigation on fluorescence and thermoluminescence of bism...

Dear Sagar S. Jagtap,

FLUORESCENCE: We can measure two types of fluorescence: prompt (PF) and delayed fluorescence (DF, also named luminescence).

Both types are emitted from PSII. PF results from deactivation/de-excitation of the lowest singlet excited states of chlorophyll a, within the photosynthetic unit (chlorophylls + light harvesting protein complexes LHC + reaction center P680 + oxygen evolving complex OEC).

The quantum yield of PF depends on photochemical (PQ) and non-photochemical quenching (NPQ) processes.

PQ can be defined as the PSII capacity to trap photons energy into excitonic energy, resulting in a excited reaction center (P680*) generating positive and negative charge pairs CP.

In NPQ, the excitonic energy is transformed into heat (sink, radiative energy dissipation).

DF is also the result of deactivation of a chlorophyll a singlet state, however, the excited state P680* is created by recombination of a previously light-separated +/-CP, and not by absorption of a photon in the LHC. Those recombination PSII CP are stored and stabilised by activation energy barriers that help to increase photosynthetic efficiency. If the temperature of the sample is increased, there is some probability that the trapped charges can overcome the barrier of the activation energy and migrate back to the reaction center chlorophyll a where they undergo charge recombination, The energy released in the recombination is transferred back to the bulk chlorophyll and emitted as a thermoluminescence photon or converted into heat in a radiationless transition. Those stored recombining CP can be revealed by the so-called thermoluminescence bands, by alternating progressive warming, illumination, and dark periods, so the emitted luminescence is recorded during the "dark" intervals.

THERMOLUMINESCENCE (TL) is the emission of light induced by heating of preilluminated materials. Luminescence emission increases with temperature (please, have a look at the Transition state Theory and specially, the Arrhenius-Eyring equation). Thus, the CP are depleted by recombination.

The S states of the OEC, Pheophytin, QA and QB of PSII contribute to the generation of TL.

Prof. Demeter and Govindje wrote a minireview on thermoluminescence in plants,

Article Thermoluminescence in plants

Article Thermoluminescence in plants

I hope this may help you.

Ronald

Incandescence or thermoluminescence is the production of light from heat. ... Phosphorescence and fluorescence are the processes of converting invisible UV energy emitted normally from an electrical discharge into visible light. Material called phosphors cause UV energy to make this transition into visible light.

https://www.sciencedirect.com/topics/materials-science/thermoluminescence