Size‐Controlled Synthesis of Cu_2‐xE (E = S, Se) Nanocrystals with Strong Tunable Near‐Infrared Localized Surface Plasmon Resonance and High Conductivity in Thin Films

Abstract

A facile method for preparing highly self‐doped Cu2‐xE (E = S, Se) nanocrystals (NCs) with controlled size in the range of 2.8–13.5 nm and 7.2–16.5 nm, for Cu2‐xS and Cu2‐xSe, respectively, is demonstrated. Strong near‐infrared localized surface plasmon resonance absorption is observed in the NCs, indicating that the as‐prepared particles are heavily p‐doped. The NIR plasmonic absorption is tuned by varying the amount of oleic acid used in synthesis. This effect is attributed to a reduction in the number of free carriers through surface interaction of the deprotonated carboxyl functional group of oleic acid with the NCs. This approach provides a new pathway to control both the size and the cationic deficiency of Cu2‐xSe and Cu2‐xS NCs. The high electrical conductivity exhibited by these NPs in metal‐semiconductor‐metal thin film devices shows promise for applications in printable field‐effect transistors and microelectronic devices.

Cation exchange synthesis and optoelectronic properties of type II CdTe–Cu2−xTe nano-heterostructures

“…S3c, † ESI). 79 We also remark here that upon partial cation exchange the photoluminescence (PL) from the CdTe sub-units in the CdTe-Cu 2Àx Te NRs gets signicantly quenched and blue-shis (Fig. S4, † ESI).…”

Semiconducting and Plasmonic Copper Phosphide Platelets

“…Similar absorption in this region has previously been reported for Cu 2 S and Cu 2 Se, and is mostly due to localized surface plasmon resonance (LSPR). [5][6][7][8]18] However, this has been observed for the first time in Cu 3 P. This plasmonic absorbance is further supported by the tuning of the absorption energy with variation of the dispersion mediums of different refractive index. A typical example of solutions in CCl 4 , CS 2 , and C 2 Cl 4 suggests that the absorption (Figure 4 c).…”

“…[1][2][3][4][5][6][7][8][9][10][11][12][13] Furthermore, materials with rectification properties remain one of the most demanding materials in recent times. [1][2][3][4][14][15][16][17] Very recently, semiconducting nanomaterials with tunable plasmonic absorption properties have also been reported; [5][6][7][8][18][19][20][21][22] these may further expand the already widespread applications of these nanomaterials in diverse research fields, including both in biology and device-based technologies. Hence, materials with several of these new properties are in demand for their implementation in different developing modern technologies.…”

Fully Solution‐Processed Conductive Films Based on Colloidal Copper Selenide Nanosheets for Flexible Electronics

“…The conductivity values measured in this work are much higher than those reported previously on fi lms of Cu 2−x Se NCs, in which the NCs were coated either with oleylamine/oleic acid molecules (10 −9 S·cm −1 ) or with mercaptopropionic acid (10 −6 S·cm −1 ). [ 23 ] This can be attributed to a much higher value of x, i.e. much larger number of copper vacancies in the particles resulting in their high degenerately doping levels.…”