Combined simulation and experimental study on spectral absorbance of partially disordered MoSe2 nanospheres

Abstract

It is important to clarify the role and possible applicability of partially disordered structures in photonics, but there is still a lack of an effective method for it. Here, we investigate partially disordered MoSe2 nanospheres experimentally regarding their morphology and absorption spectrum in broadband wavelengths and propose an optical simulation with three-dimensional finite-difference time-domain method to explain the crucial impacts of morphological parameters on optical responses. The experimental spectral absorbance of MoSe2 nanospheres reveals a strong light-absorbing character in broadband wavelengths. The simulated spectral curves coincide with the experimental results by adjusting morphological parameters, i.e. the statistics of size and the number of layer, and the linear correlation coefficient between the simulated and experimental spectral curves is up to 0.94. The disorder plays a key role in the high light-absorption feature, and the feature originates from anti-reflection, defective state absorption, multiple light scattering and coherent diffusion effects. The results not only deepen the understanding of disordered photonics in semiconductor nanostructures, but also provide a simulation approach to optimize experimental designs.