Patent ID: 9334443
Filing Date: 2016-05-10
CPC Classification: C01G,C01P,C09K

Claim Text:
1. A process of forming CsSnI 3 powder, comprising the steps of: (a) forming a CsI solution by dissolving CsI powder of purity equal to 99.999% in an organic solvent consisting of at least one of N,N-dimethylformamide (DMF), γ-butyrolactone (GBL) and mixtures thereof; (b) forming a SnI (c) adding the SnI (d) stirring said composite solution for at least one hour to obtain a homogeneous CsSnI (e) aging said precursor solution at least for a predetermined time period after said stirring step; (f) heating said precursor solution following said aging step at a temperature within the range of 50° C. to 250° C. until all the solvent is evaporated to form CsSnI (g) the process steps (a) to (f) are performed in a substantially inert environment including a protective gas and water vapor and oxygen each at a level below 1 ppm.