بررسي رفتار اپتيكي نقاط كوانتومي پروسكايت CsPbBr3 در حضور و بدون حضور نانوذرات نقره

Investigating the optical behavior of CsPbBr3 perovskite quantum dots in the presence an‎d absence of silver nanoparticles

فيزيك

CsPbBr3 halide perovskite quantum dots have numerous applications in photonics an‎d optoelectronics due to their high photoluminescence quantum yield, narrow emission ban‎dwidth, an‎d tunable emission wavelength. Improving the optical efficiency of CsPbBr3 halide perovskite quantum dots is possible in the presence of the surface plasmons of metallic nanoparticles, such as silver. In this dissertation, the production of CsPbBr3 halide perovskite quantum dots an‎d silver nanoparticles is accompanied by an investigation into the method of creating a hybrid system consisting of silver nanoparticles an‎d CsPbBr3 halide perovskite quantum dots. The overlap between the photoluminescence spectrum peak of the CsPbBr3 halide perovskite quantum dots an‎d the plasmonic resonance peak of the silver nanoparticles leads to the modification of the optical properties of the components within this system. CsPbBr3 halide perovskite quantum dots have been synthesized in sizes of 7.4 nm an‎d 8.7 nm. By increasing the size of the CsPbBr3 halide perovskite quantum dots, the ban‎dgap energy decreases from 2.38 to 2.32. Furthermore, by increasing the size of these quantum dots, the photoluminescence peak shifts from 522 nm to 533 nm, an‎d the optical density peak shifts from 510 nm to 528 nm. Silver nanoparticles are created through two methods: glancing angle deposition (GLAD) an‎d ion exchange. To prevent direct contact between the quantum dots an‎d the metallic nanostructure deposited at a glancing angle, a PMMA spacer layer has been used, which causes an increase in the photoluminescence of the CsPbBr3 halide perovskite quantum dots in the hybrid system. In Ag+/Na+ ion-exchanged glasses, the glass matrix acts as the spacer. In the hybrid system consisting of perovskite quantum dots an‎d ion-exchanged glasses, Forster energy transfer from CsPbBr3 perovskite quantum dots to silver nanoparticles results in a 23 percent increase in the photoluminescence of the ion-exchanged glasses. By annealing the ion-exchanged glasses at 450°C, silver nanoparticles are formed. In the hybrid system consisting of perovskite quantum dots an‎d the annealed samples, the near-field generated by the silver nanoparticles an‎d the Förster energy transfer from CsPbBr3 perovskite quantum dots to silver nanoparticles result in a 42 percent enhancement in the photoluminescence of the annealed sample.

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