Annealing and deposition time effects on the structural, optical, and electricalproperties of indium sul de thin lms produced by chemical bath depositionmethod

Abstract

Indium sul de thin lms were deposited onto indium-doped tin-oxide substrates with different deposition times(60 h, 63 h, 66 h, and 69 h) at room temperature by using a chemical bath deposition method to obtain new structures forsolar cells. The lm obtained at 60 h was annealed at 400◦C for 1 h in nitrogen media. The crystallographic structureof the lms was observed via the X-ray diffraction pattern while the size and shape of the grains were characterized byscanning electron microscopy. Moreover, the optical transmission spectra of the lms were obtained at room temperaturein the wavelength range of 300{1100 nm. After the lms were annealed, the optical transmission decreased from 52%to 26% at a wavelength of 550 nm. With increasing lm thickness and grain size, the direct and indirect optical bandgap of the InS lms decreased from 2.31 eV to 2.19 eV and from 1.89 eV to 1.75 eV, respectively. The refractive index,extinction coefficient, and dielectric constant of the lms were determined. The sheet resistivity of the lms decreasedfrom 33 Ω cm to 28 Ω cm with increasing grain size.