First-Principles Insights into the Interface Chemistry between 4-Aminothiophenol and Zinc Phosphide (Zn₃P₂) Nanoparticles

Abstract

Accurate prediction of the structures, stabilities, and electronic structures of hybrid inorganic/organic systems is an essential prerequisite for tuning their electronic properties and functions. Herein, the interface chemistry between the 4-aminothiophenol (4ATP) molecule and the (001), (101), and (110) surfaces of zinc phosphide (Zn3P2) has been investigated by means of first-principles density functional theory calculation with a correction for van der Waals interactions. In particular, the atomic-level insights into the fundamental aspects of the 4ATP adsorption, including the lowest-energy adsorption configurations, binding energetics, structural parameters, and electronic properties are presented and discussed. The 4ATP molecule is demonstrated to bind most strongly onto the least stable Zn3P2(001) surface (E ads = −1.91 eV) and least strongly onto the most stable Zn3P2(101) surface (E ads = −1.21 eV). Partial density of states analysis shows that the adsorption of 4ATP on the Zn3P2 surfaces is characterized by strong hybridization between the molecule’s sulfur and nitrogen p-orbitals and the d-orbitals of the interacting surface Zn ions, which gave rise to electron density accumulation around the centers of the newly formed Zn–S and Zn–N chemical bonds. The thermodynamic crystal morphology of the nonfunctionalized and 4ATP-functionalized Zn3P2 nanoparticles was obtained using Wulff construction based on the calculated surface energies. The stronger binding of the 4ATP molecule onto the less stable (001) and (110) surfaces in preference to the most stable (101) facet resulted in the modulation of the Zn3P2 nanocrystal shape, with the reactive (001) and (110) surfaces becoming more pronounced in the equilibrium morphology.

Electronic Structure and Surface Properties of Copper Thiocyanate: A Promising Hole Transport Material for Organic Photovoltaic Cells

“…The reduction in the work function upon DMSO adsorption may be rationalised by considering the fact that the DMSO adsorption is characterised by electron density rearrangement, which smoothens the surface electric charge distribution according to the Smoluchowski effect [ 63 , 64 ]. Similar results have been reported for other organic functionalised surfaces [ 65 , 66 , 67 , 68 ]. These calculated work functions compare closely with experimental measurements, which report the Φ of CuSCN in the range of 5.0–5.4 eV [ 69 , 70 , 71 , 72 ].…”

The Advantage of Nanowire Configuration in Band Structure Determination

“…[29][30][31][32][33][34][35] Current record solar cells have efficiencies of up to 6%, [36] which is well below their theoretical limit (>30%), [37] illustrating the improvement potential of this material. [37] While recent breakthrough in synthesis of highly crystalline Zn 3 P 2 using innovative nanoscale methods (e.g., selective area epitaxy) [35,38,39] have rekindled the interest in the material, major limitations related to controllable optoelectronic properties [31,32,34,[40][41][42][43][44][45][46][47] and device design still need to be resolved. This is the reason why precise determination of the electronic properties of Zn 3 P 2 is of uttermost importance.…”

Unravelling the early oxidation mechanism of zinc phosphide (Zn3P2) surfaces by adsorbed oxygen and water: a first-principles DFT-D3 investigation

“…Functionalization of Zn 3 P 2 nanoparticles can enhance their surface stability against temperature and possible oxidation in the presence of oxygen and moisture that could result in their degradation. 60…”