Efficiency Enhanced Colloidal Mn-Doped Type II Core/Shell ZnSe/CdS Quantum Dot Sensitized Hybrid Solar Cells

Abstract

Colloidal Mn-doped ZnSe/CdS core/shell quantum dots (QDs) are synthesized for the first time and employed as a strategy to boost the power conversion efficiency of quantum dot sensitized solar cells. By using Mn-doping as a band gap engineering tool for core/shell QDs an effective improvement of absorption spectra could be obtained. The mid-states generated by a proper Mn content alleviate carrier separation and enhance the electron injection rate, thus facilitating electron transport to the TiO2substrate. It is demonstrated that a device constructed with 0.25% Mn-doped ZnSe/CdS leads to an enhancement of the electron injection rate and power conversion efficiency by 4 times and 1.3, respectively.

Improving Charge Carrier Delocalization in Perovskite Quantum Dots by Surface Passivation with Conductive Aromatic Ligands

“…The average lifetime of the MAPbBr 3 QDs on conductive ITO-TiO 2 and insulating borosilicate glass was used to determine the electron-transfer rate constant ( K et ) from the equation − where τ (PQD+TiO 2 ) and τ (PQD) are the fluorescence decay on ITO-TiO 2 and borosilicate substrate, respectively. For BZA-BA-MAPbBr 3 , APTES-OA-MAPbBr 3 , and OCTA-OA-MAPbBr 3 QDs, the electron injection rate constants are calculated to be 55.7, 4.35, and 1.99 μs −1 , respectively.…”

Simulation-Based Optical Spectra Analyses and Synthesis of Highly Monodispersed Mn-Doped ZnSe Nanocrystal

“…4,[13][14][15] As compared to pure semiconductor nanocrystals, transition metal ion-doped nanocrystals have many advantages, such as zero self-quenching due to the large Stokes shift 12,[16][17][18] (energy di®erence between the absorption spectrum and the emission band), and very high thermal, 19 chemical 5 and photochemical stability. 3,[20][21][22] The d-dots are the ideal emissive materials for applications requiring signi¯cant power and/or high density of nanocrystals, such as biological imaging 21,[23][24][25] light emitting diode (LED), 1,12,26 optoelectronics, 24-27 laser 1 and solid-state lighting. 28 On account of their potential applications, Mn:ZnSe d-dots, clusters have been investigated via theoretical calculations 29,30 and experiments.…”