The investigation of the kinetics of the losses of nonequilibrium current carriers in Cu$_{2-\delta}$NiSnS$_{4}$ (0 $\le\delta\le$ 0.2) quaternary copper compounds

By solid-phase synthesis from elemental Cu, Ni, Sn, and S samples Cu$_{2-\delta}$NiSnS$_{4}$ was prepared. The parameters of their crystal lattice have been refined. The lifetimes of photogenerated current carriers in Cu$_{2-\delta}$NiSnS$_{4}$ were estimated for the first time by the contactless time resolved microwave photoconductivity method. This times turned out to be $\tau$ $\approx$ 7 ns, which is comparable with the literature data for the times in kesterites CZTS. Herewith, in kinetics of loses of photogenerated cureent carriers is observed predominance of bimolecular recombination processes over capture processes.