Ultrafast and nonlinear optical properties of two-dimensional CdSe nanostructures prepared using MoS2 nanosheets as template

Abstract

Two-dimensional (2D) materials have attracted tremendous research interest because of their unique optical, electronic, and mechanical properties which make them suitable building blocks for various electronic and optoelectronic applications. The heterostructures formed by 2D semiconductors can play an important role in modern semiconductor industry. Here, we have grown 2D-CdSe structures over MoS2 nanosheets via successive ion layer adsorption and reaction method. The dynamics of photoinduced charge carriers in 2D-CdSe nanostructures have been investigated using femtosecond transient absorption spectroscopy. Our photophysical studies infer that charge carrier recombination is monomolecular at low and bimolecular at high excitation densities. Nonetheless, femtosecond Z-scan technique was employed to demonstrate optical limiting behavior of 2D-CdSe films. This study will open up a new avenue of designing 2D nanomaterials for optoelectronic applications.