Low‐temperature electrical resistivity of cupric telluride (CuTe) thin films

Abstract

Thin films of cupric telluride (CuTe) of thickness from 50 to 200 nm have been prepared using a thermal evaporation technique onto well‐cleaned glass substrates kept at 300 K under a vacuum better than 2 × 10–5 mbar. After annealing the deposited films at 375 K for an hour, the resistivity of these films and that of bulk CuTe were measured using the four‐probe technique as a function of temperature from 80 to 310 K. It is found that the bulk sample of CuTe exhibits metallic behaviour and the thin films show semiconducting be‐ haviour. Activation energies of the films have been evaluated and are in the range 0.05 and 0.15 eV. The metallic behaviour of bulk CuTe down to 4 K indicates that the variable range hopping mechanism is absent in CuTe at least down to liquid helium temperature. X‐ray diffraction analysis confirmed the composition and polycrystalline nature of the CuTe films. The grain size of CuTe thin films, estimated from atomic force microscopy measurements, is around 40 nm. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Electrodeposition and Characterization of CuTe and Cu2Te Thin Films

“…Figure 7 shows the variation of ( ℎ]) 2 with ℎ] for deposited CuTe and Cu 2 Te. By extrapolating straight line portion of ( ℎ]) 2 against ℎ] plot to = 0, the optical band gap energy was found to be 1.51 eV for CuTe and 1.12 eV for Cu 2 Te films, comparable with the value reported earlier for CuTe and Cu 2 Te thin film [1,15].…”

“…In these experiments, the potential scanning was started at 0 V to avoid the oxidative stripping of Cu. Similar to most literatures, two reduction peaks are seen: peak C2 at about −0.21 V based upon the four-electron process for Te reduction shown in reaction (1) and peak C3 at about −0.46 V, which should be corresponded to bulk Te (0) reduction to Te 2− , as reaction (2) shows…”

“…Semiconducting compounds such as I-VI copper chalcogenides are widely used in the fabrication of photoconductive and photovoltaic devices [1]. Copper based chalcogenides exhibited the characteristics of a p-type semiconductor for the vacancies of copper and are potential materials for wide applications.…”

CuTe: Remarkable Bonding Features as a Consequence of a Charge Density Wave

“…No manifestation of a Peierls-like distortion of the Te chains has previously been found for this compound, and metallic conductivity was determined experimentally. [4,5] In recent X-ray diffraction experiments on single crystals, however, we discovered that the structure of CuTe indeed exhibits a charge density wave (CDW)-type modulation. The modulation leads to a significantly different bonding situation as compared to the average or non-modulated structure.…”

Influence of substrate temperature on the structural, morphological, optical and electrical properties of copper telluride thin films prepared by electron beam evaporation method

“…In the present work the film deposited at 500 C shows relatively low resistivity of 1.36 10 -3  cm. Neyvasagam et al [23] reported electrical resistivity of CuTe thin film is in the range of 3.45  10 -1  cm -4.693  10 -1  cm. Pathan et al [5] reported dark electrical resistivity for the mixed phase film (CuTe, Cu 2 Te and Cu 2-x Te) measured at RT is of the order of 10  cm.…”