Density Functional Theory Studies on Dimension-Controlled Self-Assemblies from Cadmium Telluride Nanoclusters: Implications for Solar Cell Applications

Abstract

We report a first-principles theory-based study of the stability, electronic structure, and optical properties of cluster-assembled materials in various one-dimensional (1D), two-dimensional (2D), and three-dimensional (3D) nanostructures using a cagelike Cd9Te9 cluster as the superatom. The bulk 3D self-assemblies form in 2D stacked structures for different cubic lattices. The face-centered stacking is the most stable compared to the simple cubic, body-centered, and zinc blende-type stackings. The 2D stacks are formed as cluster-assembled monolayers, and the monolayer derived from the face-centered structure is the most stable. Further, the cluster chains (or wires) with more number of intercluster bonds are also seen to be dynamically stable. Due to quantum confinement, the energy gap of CdTe self-assemblies increases from the 3D to 2D to 1D nanostructures. The electronic structure, band gap, dielectric constant, and absorption spectra along with the phonon dispersions are discussed for these self-assembled nanostructures. The dielectric properties of these self-assembled nanostructures point to their potential applications in fabricating solar cells.

Si5-pentagonal rings and Y-shaped Si4building blocks in Li32Si18system: similarities with the crystalline Zintl phase Li12Si7

“…8,13–16 The assembly of some clusters could allow the building of new materials with the possibility of tuning their properties. 17–27 However, for this to be feasible, the clusters to be assembled must retain their structural identity when piled up, as Khanna and Jena first outlined when they coined the term “cluster assembled materials” (CAMs). 22…”