Effect of chemical bath deposition parameters on the growth of pbs thin films for tfts applications

A. CARRILLO-CASTILLO, F. S. AGUIRRE-TOSTADO, A. SALASVILLASENOR, , I. MEJIA, B. E GNADE , M. SOTELO-LERMA , M.A. QUEVEDO-LOPEZ . Centro de Investigacion en Materiales Avanzados, S. C. Alianza Norte 202, Parque de Investigacion e Innovacion Tecnologica, Apodaca, Nuevo Leon, C.P. 666000, Mexico Department of Materials Science and Engineering, The University of Texas at Dallas. 800 West Campbell Rd, Richardson TX 75083, USA Departamento de Investigacion en Polimeros y Materiales. Universidad de Sonora. Hermosillo, Sonora, C.P. 83000, Mexico Lead sulfide (PbS) thin films were prepared by chemical bath deposition (CBD) as function of deposition time, pH and deposition rate and the impact of the resulting film structure on the thin film transistor (TFT) electrical characteristics was evaluated. Structure and morphology were investigated by X-ray diffraction (XRD) and scanning electron microscopy respectively (SEM). The deposited films show a cubic phase (galena) with an average crystallite size of ~25 nm. Three different PbS deposition conditions were evaluated in TFTs using source and drain gold contacts. The best electrical performance was observed for films deposited at high deposition rates. These transistors, showed field effect mobility and threshold voltage of ~3x10 cm/V-s and ~6 V, respectively.