Absorption enhancement by transition metal doping in ZnS

Abstract

Transition metal doping is an effective tool for controlling optical absorption in ZnS and hence the number of photons absorbed by photovoltaic devices. By using first principle density functional calculations, we compute the change in number of photons absorbed upon doping with a selected transition metal and found that Ni offers the best chance to improve the performance. This is attributed to the formation of defect states in the band gap of the host ZnS which give rise to additional dipole-allowed optical transition pathways between the conduction and valence band. Analysis of the defect level in the band gap shows that TM dopants do not pin Fermi levels in ZnS and hence the host can be made n- or p- type with other suitable dopants. The measured optical spectra from the doped solution processed ZnS nanocrystal supports our theoretical finding that Ni doping enhances optical absorption the most compared to Co and Mn doping.

DFT Study about the Effect of Doping on the Properties of GaSb Material and Designing of High‐Efficiency Infrared Photodetector

“…Metal doping is an effective tool for controlling the optical absorption in the GaSb material and hence the photons absorbed by the photonic devices. [ 31 ] In our study, we found that Ge and Zn doping shows the best chance to improve performance because dipole active states are formed in the bandgap of GaSb.…”

Emerging II-VI wide bandgap semiconductor device technologies

“…N, P, and As for p-type ZnS nanocrystals [151] Ni, Mn, Cu, Al for ZnS [152][153][154][155][156] colloidal Mn for CdS/ZnS, CdZnS QDs [157,158]. Fe for ZnS, CdTe, CdMnTe, ZnCdTe [159]. Mn for ZnSe nanocrystals [160].…”

Continuous-Flow Synthesis of Zn1–xMnxS Nanoparticles at Ambient Conditions

“…12 By doping or substituting Zn with Mn, the photon absorption efficiency is improved, which together with a lowering of the band gap favors photocatalytic degradation under visible light. 4,6,7 Furthermore, Mn doping creates trap states, which prolong the electron−hole recombination time. 4,7,12,13 Three polymorphs of ZnS have been reported.…”

“…4,6,7 Furthermore, Mn doping creates trap states, which prolong the electron−hole recombination time. 4,7,12,13 Three polymorphs of ZnS have been reported. Sphalerite is the stable allotrope under ambient conditions, while wurtzite is stable at high temperatures.…”