Growth and characterization of Cu3SbSe4 thin films through thermally diffusing Sb2Se3 – CuSe by chemical bath deposition (CBD)

Abstract

In the present work, Cu3SbSe4 thin films have been successfully synthesized by chemical bath deposition (CBD) involving a sequential deposition of antimony selenide (Sb2Se3) and copper selenide (CuSe) films and then annealing in a vacuum atmosphere. The influence of CuSe deposition time on the previously deposited Sb2Se3 films was investigated to obtain the ternary phase. A study of the structural, morphological, optical and electrical properties of these films was carried out using appropriate characterization techniques. X-ray diffraction analysis revealed that the films show a tetragonal crystalline crystalline structure corresponding to the Permingeatite phase (Cu3SbSe4). The crystal size increases with the CuSe deposition time. It is identified by Raman spectroscopy that at low CuSe deposition times a low concentration of Sb2Se3 coexists in the thin film. The optical band gap energy of these films was evaluated in the range of 0.67–1.18 eV, decreasing by increasing CuSe deposition time. By field-emission scanning electron microscopy (FESEM) a morphological study was carried out, observing that by increasing the deposition time of CuSe there is an increase of agglomerates and decrease the porosity in the samples. An elemental analysis was carried out by energy dispersive X-ray spectroscopy to observe the composition and elemental distribution in the ternary compound. The films showed a p-type electrical conductivity with values between 0.417 and 55.55 (Ω cm−1). The mobility and carrier density were performed by Hall Effect and Thermoelectric measurements observing a slight increase in the values by increasing the time of CuSe deposition. All results obtained for thin films of Cu3SbSe4 suggest that it could be used as an absorber material in a solar cell or thermoelectric material.