Flash Evaporation and Thin Films of Cuprous Sulfide, Selenide, and Telluride

Abstract

Films of Cu1.8S have been made by flash evaporation. They have a resistivity of 6.2×10−4Ω·cm and an absorption coefficient to 1.5 eV radiation of 1.13×103 cm−1. The corresponding quantities for Cu1.8Se are: 1.6×10−4Ω·cm, and 1.18×103 cm−1. The resistivity of Cu1.8Te films increases with time. It is found that if during flash evaporation the ratio of partial pressures of Cu and Se at the substrate fluctuates then the film does not have the composition of the charge. Cu1.8S has potential applications for producing transparent conducting coatings on substrates which cannot be heated above room temperature.

High-temperature conductivity in chemical bath deposited copper selenide thin films

“…Ellis [27] has reported the determination of film composition (by electron diffraction) and showed the linear dependence of lattice constant on nonstoichiometric factor x for Cu 2Àx Se phase. Using Ellis plot, the compositional analysis of the deposited representative Cu 2Àx Se film having lattice constant a ¼ 5:826 ( A has been carried out (Fig.…”

“…Cubic Cu 2Àx Se films with non-stoichiometric factor, x up to 0.20 is considered as the most stable form [2]. Earlier workers [10,27] reported that lattice constant a-and d-spacing for (0 2 2) plane of Cu 2Àx Se films are linearly dependent on the composition. For cubic Cu 2Àx Se phase, the lattice constant a is a strong function of x, and a varies from 5.86 to 5.74 Å for x values from 0.00 to 0.20, respectively [2].…”

“…Electrical studies on Cu 2Àx Se thin films have been carried out by earlier researchers [2,8,9,[14][15][16]18,19,21,27,28]. Electrical resistivity of Cu 2Àx Se films have been measured in the temperature range of 303-503 K and a voltage range of 8-20 V. Fig.…”

“…Copper selenide thin films can be obtained by a variety of techniques such as vacuum evaporation [14,22,23], electrodeposition [12,24,25], flash evaporation [26,27], solid-state reaction [28,29], electroless deposition [3,8,30], cathodic deposition [31], selenization [32,33] and chemical bath deposition [2,6,7,9,[15][16][17][18]. Of the various techniques, the chemical bath deposition technique, which is a non-vacuum electroless technique, has many advantages such as simplicity, no requirement for sophisticated instruments, minimum material waste, economical way of large-area deposition, no need of handling poisonous gases like H 2 Se or Se vapour and the possibility of room temperature deposition.…”

Structural, morphological, optical and electrical properties of Cu0.87Se thin films coated by electron beam evaporation method

“…Okimura et al [6] prepared Cu 2-x Se-Si junction by conventional vacuum evaporation method and reported that the conversion efficiency of the junction is about 8.3 and 8.8 % for 3-and 2-mm-diameter Cu 2-x Se layer, respectively. Several chemical and physical methods such as chemical bath [2,[7][8][9][10][11], aerosol-assisted chemical vapor deposition [12,13], electroless [14], solgel [15], electrochemical deposition [16], electrophoretic deposition [17], brush electroplate deposition [18], cathodic deposition [19], dip coating [20], spray pyrolysis [21], vacuum co-evaporation [22], vacuum evaporation [6,23], pulsed laser deposition [4,24], selenization [25], magnetron sputtering [26], flash evaporation [27] and reactive evaporation [28] methods have been employed to deposit copper selenide thin films. Ting and Lee [17] prepared Cu 2-x Se nanocrystals by one-pot solution-phase method.…”