Realization of semiconducting Cu₂Se by direct selenization of Cu(111)*

Abstract

Bulk group IB transition-metal chalcogenides have been widely explored due to their applications in thermoelectrics. However, a layered two-dimensional form of these materials has been rarely reported. Here, we realize semiconducting Cu2Se by direct selenization of Cu(111). Scanning tunneling microcopy measurements combined with first-principles calculations allow us to determine the structural and electronic properties of the obtained structure. X-ray photoelectron spectroscopy data reveal chemical composition of the sample, which is Cu2Se. The observed moiré pattern indicates a lattice mismatch between Cu2Se and the underlying Cu(111)- 3 × 3 surface. Differential conductivity obtained by scanning tunneling spectroscopy demonstrates that the synthesized Cu2Se exhibits a band gap of 0.78 eV. Furthermore, the calculated density of states and band structure demonstrate that the isolated Cu2Se is a semiconductor with an indirect band gap of ∼ 0.8 eV, which agrees quite well with the experimental results. Our study provides a simple pathway varying toward the synthesis of novel layered 2D transition chalcogenides materials.

Monolayer Cu2Se: a topological catalysis in CO2 electroreduction

“…In experimental synthesis [39], monolayer Cu 2 Se have been successfully produced, and intriguingly, they exhibit the characteristics of a 2D NLSM. As illustrated in figure 1(a), these nanosheets adopt a hexagonal lattice structure, with each unit cell containing two copper (Cu) atoms and one selenium (Se) atom.…”

Morphotaxy of Layered van der Waals Materials

“…The authors also reported a similar scheme for realizing environmentally stable TiSe 2 and other ambient-sensitive selenides. Starting with another transition metal, Yang et al reported the synthesis of semiconducting Cu 2 Se via selenization of Cu(111) in ultrahigh vacuum, resulting in a layered phase of Cu 2 Se that was markedly distinct from its regular unlayered bulk phase . This 2D Cu 2 Se structure exhibited a band gap of 0.74 eV, again underscoring that phases distinct from naturally occurring materials can emerge using morphotaxial approaches.…”

Comparative Study of the Co-Occurring Alternaria and Colletotrichum Species in the Production of Citrus Leaf Spot

“…The confusion of ABS and Anthracnose, or Alternaria species and Colletotrichum species, for the symptoms of citrus brown spot has lasted for over a decade in China, but still lacks a conclusion [8,9]. ABS was first observed in 2003, and reported in 2010, in Yunnan Province, China [10].…”

“…ABS was first observed in 2003, and reported in 2010, in Yunnan Province, China [10]. After that, the disease has been successively reported as an outbreak in several other citrus production areas in China, such as Chongqing [7], Zhejiang [11], Guangxi [9], and Fujian [12]. However, the diseased citrus trees (C. reticulata var.…”

“…Fungi 2023, 9, x FOR PEER REVIEW 2 of 13 leaves; those leaves, infected by ABS, may be colonized by Colletotrichum gloeosporioides as a secondary pathogen and a saprophyte [3,7]. The confusion of ABS and Anthracnose, or Alternaria species and Colletotrichum species, for the symptoms of citrus brown spot has lasted for over a decade in China, but still lacks a conclusion [8,9]. ABS was first observed in 2003, and reported in 2010, in Yunnan Province, China [10].…”