Abstract
The hot phonon bottleneck effect and the reduced carrier-phonon interactions in quantum-confined systems would lead to long-lived excitonic carrier. Importantly, these phenomena prevent the carrier energy dissipation, and consequently improve the efficiency of optoelectronic devices like solar cells. Aiming this, the excellent sensitizing properties of bismuth modified lead sulphide (Bi:PbS) quantum dots (QDs) with reduced carrier-phonon interactions are demonstrated. Further, the multiple excitonic transition states are probed from the derivatives of absorbance spectra. In the final section, both Fano interaction analysis and Huang-Rhys factor confirms the minimum carrier-phonon coupling in Bi:PbS QDs. The phonon lifetime is calculated by the Cusco equation and the obtained results endorse that Bi:PbS QDs are excellent sensitizers for solar cell applications.