Excited‐State Charge Transfer in Covalently Functionalized MoS₂ with a Zinc Phthalocyanine Donor–Acceptor Hybrid

Abstract

The functionalization of MoS 2 is of paramount importance for tailoring its properties towards optoelectronic applications and unlocking its full potential. Zinc phthalocyanine (ZnPc) carrying an 1,2-dithiolane oxide linker was used to functionalize MoS 2 at defect sites located at the edges.T he structure of ZnPc-MoS 2 was fully assessed by complementary spectroscopic,t hermal, and microscopyi maging techniques. An energy-level diagram visualizing different photochemical events in ZnPc-MoS 2 was established and revealed ab idirectional electron transfer leading to ac harge separated state ZnPcC + -MoS 2 C À .M arkedly,e vidence of the charge transfer in the hybrid material was demonstrated using fluorescence spectroelectrochemistry.Systematic studies performed by femtosecond transient absorption revealed the involvement of excitons generated in MoS 2 in promoting the charge transfer, while the transfer was also possible when ZnPc was excited, signifying their potential in light-energy-harvesting devices.

Unveiling the Photoinduced Electron‐Donating Character of MoS2 in Covalently Linked Hybrids Featuring Perylenediimide

“…Next, reaction between the two species in N,Ndimethylformamide (DMF) furnished MoS 2 -PDI hybrid material 3 (Scheme 1), in which S-vacancies at the periphery of MoS 2 are occupied by the Satoms of the ring as part of PDI derivative. [3,[15][16][17] After completion of the reaction, total removal of excess 2,f rom the powder residue obtained, was secured by filtration over PTFE membrane filter (0.2 mmpore size) and extensive washing with dichloromethane,a se videnced upon blank absorbance of the filtrate ( Figure S7).…”

“…Therefore,custom-synthesis enables PDIs to excel in plethora of cutting-edge technological applications,s uch as organic transistors, [12] photovoltaics [13] and photonics. [14] Based on our previously reported series of covalently functionalized MoS 2 with organic photoactive species,d ifferent photophysical response has been registered for the various MoS 2 based materials.N amely,t he MoS 2 entity may act as electron and/or energy acceptor, [15] energy reflector [16] or bi-directional electron acceptor, [17] based on the nature of its photoactive counterpart. Furthermore,t here is as carce literature report on aM oS 2 /PDI interfacial dipole heterosystem, formed by non-covalent interactions between the two entities lacking significant insight into MoS 2 charge transfer properties.…”

Effect of the Interfacial Energy Landscape on Photoinduced Charge Generation at the ZnPc/MoS2 Interface

“…The type-II band alignment is consistent with other reports on the metal-Pc/ML-MoS 2 interface. 27,[43][44][45] Second, there is a much stronger band bending in the ZnPc film deposited on bulk-MoS 2 than on ML-MoS 2 . It is known that ZnPc molecules on MoS 2 have a face-on orientation.…”

Controlled Covalent Functionalization of 2 H‐MoS2 with Molecular or Polymeric Adlayers

“…Within this toolbox of new materials, TMDCs show well defined band gaps that make them particularly suitable for semiconductor technology . The development of reliable tools for the chemical modification of TMDCs is crucial to achieve their full technological potential . Decoration of TMDCs with molecular fragments via noncovalent approaches, mostly based on dispersion/solvophobic interactions, is relatively easy and has consequently led the way towards potential applications.…”