Novel design of reactor to grow CuSbS2 films by chalcogenisation of metal precursors sequentially evaporated

Abstract

This article presents details of the design, construction and operation of a low cost reactor for growth of thin films of Chalcogenide Materials used for Photovoltaic applications. This reactor allows growing any type of chalcogenide compound by chalcogenisation of their metal precursors. However its performance was tested by depositing CuSbS2 films by chalcogenisation of metal precursors sequentially deposited by evaporation. The sulfurization process includes soft annealing of the Sb/Cu stacked precursor in a controlled atmosphere mixture of argon and hydrogen gas (95% Ar and 5% H2) followed by heating in the presence of elemental sulfur, using a tubular furnace heated with infrared lamps. Chalcogenisation process is carried out by controlling the heating rate of the furnace with the help of algorithms developed using LabVIEW programming environment. Through a study of deposition parameters that included the variables, furnace heating rate, final annealing target temperature and annealing time, conditions were found to grow single-phase CuSbS2 films with good structural, optical and morphological properties. This indicates that the CuSbS2 films prepared by means the chalcogenisation routine developed in this work, could be used later as an absorbent layer in solar cells.

Keywords

• CuSbS2 thin films
• Thermal evaporation
• Soft annealing treatment
• Structural properties