Method for producing powder kesterite of Cu₂SnZnS₄ type, intended for production of active layers in thin film photovoltaic cells

摘要

The purpose of the notification is to produce a powder keg of type Cu2SnZnS4, intended for production, active layers in thin film photovoltaic cells, which consists of: that the waste materials and waste products used are first scraped in the form of two-component Cu+Sn tin bronzes and two-component Cu+Zn brass, of a known type, and the chemical composition of these materials determines the actual content of single Cu, Sn and Zn metals in the mixture, seeking to obtain the theoretical content of the kester,i.e. the molar ratio Cu:Sn:Zn = 2:1:1. In the case of a shortage of metals Zn and Sn, the missing quantity shall be supplemented by the addition of pure metal powders Sn and Zn. Subsequently, the fragmented feedstock was contained in a high-energy ball mill with a liquid dispersing in the form of high-boiling aliphatic or aromatic hydrocarbons selected from a group of hexane, toluene and xylene over a period of 30-minute to 100-hour intervals, at the rotating speed of the mill 200 to 1100 Obr/min,Then add elementary sulphur to the mixture in quantities from the stoichiometric to 100% excess of the theoretical sulphur present in the Cu2SnZnS4 Kester and then have for thirty minutes to 100 hours at the rotational speed of the ball mill 200-1100 obr/min. After completion of the process, the liquid evaporates dispersive,and the resulting mixture is heated in an inert gas atmosphere at temperatures from 400 to 700'c for a period of 0,5 to 36 hours, obtaining a powder-free, medium-sized boiler of ten to 200 nm.