Phase diagrams of the Ag-In-Se photovoltaic material system

Ternary Ag-In-Se alloys are promising photovoltaic materials. The liquidus projection and the 450 °C isothermal section of the ternary Ag-In-Se system are determined. The primary solidification phases include three terminal solid solution phases, (Ag), (In), and (Se), nine binary intermediate phases, β-(Ag₃In), ζ-(Ag₃In), γ-(Ag₉In₄), φ-(AgIn₂), β-(Ag₂Se), In₂Se₃, In₆Se₇, InSe, and In₄Se₃, and two ternary compounds, AgInSe₂ and AgIn₅Se₈. There are fourteen invariant reactions involving liquid, and seven of them are experimentally determined in this study. The reactions with the highest and lowest reaction temperatures are L + (Ag)虠 AgInSe₂ + β-(Ag₂Se) at 631.7 °C and L虠 φ-(AgIn₂) + InSe + (In) at 142.8 °C, respectively. In the 450 °C isothermal section, there are eleven tie-triangles, which are (Ag) + β-(Ag₂Se) + AgInSe₂, (Ag) + AgInSe₂ + InSe, (Ag) + ζ-(Ag₃In) + InSe, ζ-(Ag₃In) + InSe + Liquid, In₄Se₃ + InSe + Liquid, AgInSe₂ + InSe + AgIn₅Se₈, InSe + In₆Se₇ + AgIn₅Se₈, AgIn₅Se₈ + In₆Se₇ + In₂Se₃, AgIn₅Se₈ + In₂Se₃ + Liquid, AgInSe₂ + AgIn₅Se₈ + Liquid and β-(Ag₂Se) + AgInSe₂ + Liquid.