Bandgap Control of ZnSnP2 via phase transition between chalcopyrite and sphalerite

ZnSnP₂ is a promising candidate for solar absorber materials from the viewpoint of high absorption and earth-abundant constitution elements. In this paper, the crystal growth experiments with various cooling rates were carried out and we successfully obtained ZnSnP₂ crystals under every condition. The structure of grown crystals studied by XRD was indicated to be chalcopyrite-type 2, while the decrease of the degree of order was observed with the increase of cooling rate. The bandgaps of ZnSnP₂ crystals decreases with increasing the cooling rate due to the decrease of the degree of order.