UV Tuning of Cadmium Telluride Quantum Dots (CdTe QDs) – Assessed by Spectroscopy and Electrochemistry

Abstract

In this work, the electrochemical analysis (potentiometric stripping analysis – PSA, cyclic voltammetry – CV) and evaluation of fluorescence properties of cadmium telluride quantum dots (CdTe QDs) covered by mercaptosuccinic acid (MSA) were performed. Using CV it was found that average value of E of QDs is lower than 0.059 V and I is in direct correlation with square root of scan rates, therefore it can be assumed that this system represents rather reversible than quasi-reversible process. Further, it was found that nearly 1.4 electrons are exchanged in both cases, which corresponded with expected two-electron transfer. Fluorescence analysis showed that UV radiation (254 and 312 nm) significantly changes fluorescence properties of CdTe QDs in time 0 – 60 min. It was found that after 5 min of UV irradiation ( = 312 nm) the fluorescence intensity increased by 37% and at = 254 nm the increase in fluorescence intensity was even higher, by 45% (compared to the control without irradiation). UV radiation also caused a shift in the emission maximum of CdTe QDs in range 2 – 70 nm. This work opens up new ways for tuning the optical properties of QDs.

In this work, the electrochemical analysis (potentiometric stripping analysis – PSA, cyclic voltammetry – CV) and evaluation of fluorescence properties of cadmium telluride quantum dots (CdTe QDs) covered by mercaptosuccinic acid (MSA) were performed. Using CV it was found that average value of E of QDs is lower than 0.059 V and I is in direct correlation with square root of scan rates, therefore it can be assumed that this system represents rather reversible than quasi-reversible process. Further, it was found that nearly 1.4 electrons are exchanged in both cases, which corresponded with expected two-electron transfer. Fluorescence analysis showed that UV radiation (254 and 312 nm) significantly changes fluorescence properties of CdTe QDs in time 0 – 60 min. It was found that after 5 min of UV irradiation ( = 312 nm) the fluorescence intensity increased by 37% and at = 254 nm the increase in fluorescence intensity was even higher, by 45% (compared to the control without irradiation). UV radiation also caused a shift in the emission maximum of CdTe QDs in range 2 – 70 nm. This work opens up new ways for tuning the optical properties of QDs.