The impact of surface structure and band gap on the optoelectronic properties of Cu2O nanoclusters of varying size and symmetry

Abstract

A systematic characterization of Cu 2 O nanoclusters using classical electrodynamics and time-dependent density functional theory (TDDFT) is performed to investigate their response to light with the alteration of size and symmetry. Absorption and scattering play a crucial role in tuning the surface plasmon resonance (SPR), which is the focal feature of optoelectronic properties. In larger dimensions the SPR is found to be strongly influenced by scattering and in smaller NPs it is dominated by absorption. A blue shift of the SPR peak is observed with decreasing cluster size. The optical properties of Cu 2 O nanoclusters are also affected by the symmetry aspect. With the variation of size and symmetry the associated surface structure and band gap are also varied. The TDDFT calculation is performed to explore the impact of these two fundamental factors on the optoelectronic nature of (Cu 2 O) n clusters.The TDDFT study on Cu 2 O nanoclusters reveals the nature of electronic excitations in photoirradiated (Cu 2 O) n clusters for n ¼ 1, 2, and 3. The transitions involved in (Cu 2 O) n are basically categorized as ligand to metal charge transfer (LMCT) and metal to metal charge transfer (MMCT) processes. The change in absorption with varying cluster dimension and symmetry is found to be critically controlled by the relative probabilities of LMCT and MMCT processes. A competing surface reconstruction effect and occupied-virtual energy gap are also found to govern the SPR pattern of the Cu 2 O nanoclusters. All of these observations provide an appropriate guideline to tune SPR of Cu 2 O NPs for specific applications.

Utilization of shape-controlled nanoparticles as catalysts with enhanced activity and selectivity

“…The band-gap energy of Cu 2 O materials can be controlled by using different shapes. 93 When Cu 2 O cubes, cylinders, and spheres were compared, the cubes had $1 eV smaller band-gap energy than spherically shaped materials. Cu 2 O with high-index facets presented higher activity for gasphase CO oxidation.…”

Synthesis of magnetic nanoparticles by laser ablation of strontium ferrite under water and their characterization by optically detected magnetophoresis supported by BEM calculations

“…† In particular, one can see that, with increasing dimension of a nanoparticle, a shift in the extinction spectrum toward longer wavelengths can be observed. 27 These results underline the importance of considering the extinction contributions of nanoparticles of different sizes.…”

Electronic structure and spectra of (Cu2O)n–H2O complexes

“…2 Here different tubes of (Cu 2 O) n are constructed, and are shown in Fig. 2 Here different tubes of (Cu 2 O) n are constructed, and are shown in Fig.…”

“…[1][2][3][4][5] The question of Cu 2 O acting as a photocatalyst for water splitting under visible light irradiation is still open and of particular experimental interest. [1][2][3][4][5] The question of Cu 2 O acting as a photocatalyst for water splitting under visible light irradiation is still open and of particular experimental interest.…”

“…8 Similarly, the bonding of H 2 X (for X = O, S) on cluster models of CuO(111) has been investigated by DFT calculations. 1,2 The possibility of rationally tuning the optical properties of Cu 2 O through the control over the dimensions and morphologies of Cu 2 O nanostructures has stimulated a large number of efforts devoted to the fabrication of a range of Cu 2 O nanostructures, 1,2 including nanocubes, 3 nanospheres 10 and nanorings. 1,2 The possibility of rationally tuning the optical properties of Cu 2 O through the control over the dimensions and morphologies of Cu 2 O nanostructures has stimulated a large number of efforts devoted to the fabrication of a range of Cu 2 O nanostructures, 1,2 including nanocubes, 3 nanospheres 10 and nanorings.…”