Estudio de propiedades fotoeléctricas de películas delgadas de SnS y SnS:Bi

Abstract

Thin films based on Sn-S compounds are currently of great interest because of their potential applications in photovoltaic and optoelectronic devices. S and Sn are abundant in nature, inexpensive and much less toxic than most of the materials used in the industry for manufacturing solar cells. In addition to their photovoltaic properties, the chalcogenide materials such as SnS, SnS$_2$, Sn$_2$S$_3$, Sn$_3$S$_4$ and Bi$_2$S$_3$ are of great interest due to its applications in the fabrication of optoelectronic and thermoelectric devices, and as a holographic recording medium. In this work SnS and SnS:Bi thin films, with suitable properties for their use in manufacturing solar cells, were grown by a new technique of sulfurization of the metallic precursors. The deposited films were studied through transient photoconductivity measurements under illumination and decay, and photocurrent as a function of light intensity; their micro-structure was also characterized through Scanning Electron Microscopy (SEM) technique. The studies allowed establishing the effect of adding Bi on the recombination processes of free charge carriers which affect the photoconductivity of the deposited films, and to identify the types of recombination occurring in them.