A Phenomenological Model To Investigate Excitonic Effects On Photoluminescence Intensity Of Nanosilicon

Visible photoluminescence from nano-silicon is one of the most attractive and debatablernissue in recent years. Studying photoluminescence and understanding itsrnmechanism has tremendous attention due to optoelectronic applications. When thernsize of quantum dots decreases the surface area to volume ratio increases and localizedrnsurface states appears in the forbidden region. Exciton energy states are also existsrnin the same gap region. It is important to examine the combined e ects of exciton,rnlocalized surface states and quantum con nement e ects. We have explicitly integratedrnthese e ects in a phenomenological model to obtain analytical expression forrnthe photoluminescence spectra. Initially, we explicitly calculated the exciton bindingrnenergy and we incorporate the exciton contribution then combined it with quantumrncon nement model and surface states to see its e ect on photoluminescence. Accordingly,rnwe observed that taking the e ect of exciton states into account explainsrnalmost accurately the experimental photoluminescence data. The results obtained usingrnMATLAB programming. Calculations take place at room temperature on smallrnquantum dots (1 - 5 nm). In conclusion, our results are quite new and it rernect somernof the feature that has quite close correspondence with the experimental. The resultsrnare also in conformity with other theoretical and experimental investigations

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