The stability domain of the selenide kesterite photovoltaic materials and NMR investigation of the Cu/Zn disorder in Cu₂ZnSnSe₄ (CZTSe)

Bulk compounds, prepared via the ceramic route, related to Cu2ZnSnSe4 (CZTSe), a material considered for use in photovoltaic devices, were investigated using NMR spectroscopy, electron-probe microanalyses and X-ray diffraction. These materials adopt the kesterite structure regardless of the Cu and Zn contents. It is also shown that the stability domain of the copper-poor quaternary phases is wider for selenide derivatives than for sulphides. Finally, the Cu/Zn disorder level in CZTSe is found to be higher when the samples are quenched, which is reminiscent of the behaviour of the parent sulphide compounds CZTS.