Electronic structure of copper nitrides as a function of nitrogen content

Abstract

The nitrogen content dependence of the electronic properties for copper nitride thin films with an atomic percentage of nitrogen ranging from 26 ± 2 to 33 ± 2 have been studied by means of optical (spectroscopic ellipsometry), thermoelectric (Seebeck), and electrical resistivity measurements. The optical spectra are consistent with direct optical transitions corresponding to the stoichiometric semiconductor Cu 3 N plus a free-carrier contribution, essentially independent of temperature, which can be tuned in accordance with the N-excess. Deviation of the N content from stoichiometry drives to significant decreases from -5 to -50 uV/K in the Seebeck coefficient and to large enhancements, from 10~3 up to 10 O cm, in the electrical resistivity. Band structure and density of states calculations have been carried out on the basis of the density functional theory to account for the experimental results.

Thin film synthesis and properties of copper nitride, a metastable semiconductor

“…5 Stoichiometric, nitrogen-rich, and copperrich Cu 3 N materials have been previously reported. [6][7][8][9] The published electrical conductivities vary from $30 S cm À1 (ref. 10) to $10 À3 S cm À1 (ref.…”

“…For a given partial pressure of nitrogen, nitrogen activity is expected to decrease with increasing target-substrate distance due to gas-phase recombination of sputtered N species, and to decrease with increasing substrate temperature due to N 2 emission from the growing lm. While the temperature 10,11,13,17 and pressure [6][7][8]11,[17][18][19] variables of Cu 3 N growth have been investigated, the target-substrate distance effect on nitrogen activity has not been studied so far. In this work we study the effect of nitrogen activity on the synthesis, structure and properties of copper nitride by simultaneous control of the target-substrate distance and substrate temperature.…”

Surveying the Synthesis, Optical Properties and Photocatalytic Activity of Cu3N Nanomaterials

“…In contrast, for M-doped Cu 3 N (M = Sc, Ti, V, Cr, Mn, Fe, Co and Ni), the band gap becomes negligible, giving rise to the metallic character of Cu 3 N [42]. Other studies confirm a semiconducting behavior but suggest that pure Cu 3 N presents an indirect band gap of 0.32 eV and direct gaps of 1.09 and 0.87 eV, whereas for Cu 3 N-N rich compounds, a partially filled spin-resolved narrow band of new electronic bandgap states at the Fermi energy is observed [97]. This new band modifies the optical properties of Cu 3 N and makes the material susceptible to infrared absorption.…”

Development of Cu3N electrocatalyst for hydrogen evolution reaction in alkaline medium

“…Numerous efforts have been taken to synthesize copper with transition metal sulphides, carbides, phosphides and dichalcogenides to overcome this issue for improving HER performance 22 – 29 . Copper Nitride (Cu 3 N) is a metastable semiconductor that has been proposed as efficient cathodic materials for energy conversion and storage applications, because of their unique physiochemical optical, electrical and its thermal properties 30 – 32 . Cu 3 N has drawn attention in other fields like optical device storage, fuel cells, high-speed ICs, metallic microscopic links, CO 2 reduction, energy storage and energy production 30 – 32 .…”

“…Copper Nitride (Cu 3 N) is a metastable semiconductor that has been proposed as efficient cathodic materials for energy conversion and storage applications, because of their unique physiochemical optical, electrical and its thermal properties 30 – 32 . Cu 3 N has drawn attention in other fields like optical device storage, fuel cells, high-speed ICs, metallic microscopic links, CO 2 reduction, energy storage and energy production 30 – 32 . Various routes have been explored for the reduction of particle size and different morphology of Cu 3 N. For instance, Pereira et al prepared Cu 3 N from CuF 2 at 300 °C in NH 3 atmosphere.…”