Stress and interfacial/surface synergistically modulated charge transfer mechanism and nonlinear absorption properties in Ti3C2(-O)/MoS2 heterostructure

Abstract

Here, Ti3C2(-O)/MoS2 with two interface contacts were obtained by two-steps of hydrothermal (HT)/HT and HT/magnetron sputtering (MS) technique. The visualizing orientation-controlled interlayer interconnection and vertical/lateral contact modes for interface properties and light-matter coupling effect have been analyzed. The Raman spectra of Ti3C2(-O)/MoS2(HT) verified that the redshift of characteristic peak for Ti3C2(-O) was dominated by interfacial stress. The results of Ti3C2(-O)/MoS2(MS) revealed that the overall blue shift of the characteristic peak for Ti3C2(-O) and the redshift of the characteristic peak for MoS2 can be attributed to the interface charge transfer of MoS2 to Ti3C2(-O). The exciton quenching of Ti3C2(-O) and the enhancement of the C exciton transition luminescence for MoS2 were observed in the photoluminescence result. It is proved that the high-excited electrons of Ti3C2(-O) transfers to the vibration level of the conduction band of MoS2 under photoexcitation. The nonlinear absorption and transient absorption properties of Ti3C2(-O)/MoS2 heterojunction were studied by Z-scan and pump–probe technology. An additional interfacial charge transfer signal in the hybrid spectra represents the efficient interfacial charge transfer of Ti3C2(-O)/MoS2(HT) and Ti3C2(-O)/MoS2(MS). This work also provides a basic theory for the emerging heterojunctions, which is conducive to developing the potential optoelectronic devices in energy environment field.