Physical properties of CdTe:Cu films grown at low temperature by pulsed laser deposition

Abstract

CdTe:Cu films were grown by pulsed laser deposition on Corning glass slides at a substrate temperature of 300 °C. The thin films were grown using CdTe and Cu2Te powders, varying the Cu2Te concentration from 3 to 10 wt. %. The structural, compositional, optical, and electrical properties were analyzed as a function of the nominal copper concentration. X-ray diffraction shows that films have CdTe cubic phase. The compositional analysis indicates that CdTe:Cu films grown with lower Cu content have Te excess, on the other hand, films with higher Cu content have Te deficiencies. The electrical measurements showed that CdTe:Cu films grown with low Cu content present lowest resistivity.

Physical properties of electron beam evaporated CdTe and CdTe:Cu thin films

“…Our result is consistent with the report of de Moure-Flores et al, 19 where they have observed the PL emission peak localized at 1.5 eV and the Cu dopant induced red shift in peak position. Raza Khan et al 46 observed a single narrow band to band emission peak at around 805 nm for the vacuum evaporated CdTe thin film.…”

“…The decrease in optical energy band gap with increasing Cu content may be due to the occupation of Cu impurity in the host lattice, which acts as acceptor level, becomes degenerate, and the energy level shifts thereby reducing the energy band gap. 19 It can be mentioned that Abbas Shah et al 20 reported that the energy band gap of Cu doped CdTe thin films is found to decrease with the increase of Cu concentrations, which is consistent with our observation. The reduction in energy band gap may also be due to the extension of localized states in amorphous structure.…”

Structural and optical properties of CdTe-nanocrystals thin films grown by chemical synthesis

“…It is widely accepted that CdTe films with Te excess have p-type conductivity; this suggests that these films have p-type conductivity [3,20]. The most of techniques used to grow CdTe films require high growth temperature (450-600 1C); thus the high deposition temperature and the differences in vapor pressure of materials make that the CdTe films present Te excces [21].…”

Optimization of physical properties of vacuum evaporated CdTe thin films with the application of thermal treatment for solar cells

“…The properties of CdTe thin films are strongly dependent upon the fabrication techniques, annealing treatment, film thickness, substrate, CdCl 2 treatment, doping and substrate temperature. An extensive research on the structural, optical and optoelectronic properties of CdTe thin films have been carried out so far by several researchers using different deposition techniques [26][27][28][29][30][31][32][33][34][35][36]. However, thermal annealing based properties of vacuum evaporated CdTe thin films are not well understood for photovoltaic applications.…”