Deciphering Ultrafast Carrier Dynamics of Eco-Friendly ZnSeTe-Based Quantum Dots: Toward High-Quality Blue-Green Emitters.

Developing non-toxic and high-performance colloidal semiconductor quantum dots (CQDs) represents the inevitable route toward CQD-enabled technologies. Herein, the spectral and dynamic properties of heavy-metal-free ZnSeTe-based CQDs are investigated by transient absorption spectroscopy and theoretical modeling. We for the first time decode the ultrafast hot carrier trapping (<2 ps) and band-edge carrier trapping processes (∼6 ps) in the CQD system, which plagues the emission performance.

Unveiling the nonadiabatic photoisomerization mechanism of hemicyanines for UV photoprotection.

In this work, the nonadiabatic energy relaxation mechanism of hemicyanines for UV photoprotection were investigated by using the density functional theory (DFT) and time-dependent density functional theory (TDDFT) method for the first time. The absorption spectra and potential energy surfaces (PESs) of four hemicyanines with different positions of substituents were presented. The maximum absorption peaks of the four hemicyanines are located in the UVA region.

Unveiling the photoluminescence regulation of colloidal perovskite quantum dots via defect passivation and lattice distortion by potassium cations doping: Not the more the better.

In this work, we have first demonstrated that the potassium cation doping effect on photoluminescence (PL) regulation of CHNHPbBr (CHNH=MA) colloidal perovskite quantum dots (QDs) is significantly different from the other alkali cation doping effects. The PL intensity will be generally enhanced with the increase doping amounts of other alkali cations. Herein, we have unveiled that the PL of the potassium-doped perovskite QDs is initially prompted by the potassium ions doping and then inhibited with further growing doping amount of the potassium ions.