The effects of selenization temperatures on the phase formation and the photovoltaic properties of silver-ion-doped Cu(In,Ga) Se-2 (ACIGS) films were investigated. Cu2-xSe phase coexisted with CuInSe2 phase in the films as the selenization temperature was relatively low. Increasing the selenization temperatures promoted the formation of the chalcopyrite phase and increased the grain size. Upon increasing the selenization temperature to 600 degrees C, single-phased ACIGS films with a grain size of 2.1-2.2 mu m were successfully synthesized. The incorporation of Ag+ and Ga3+ ions into CuInSe2 during the phase formation of ACIGS elevated the band gaps of the films, thereby improving the open-circuit voltage (V-oc) of the solar cells. The grain growth on raising the selenization temperatures also elevated the short-circuit current (J(sc)) values owing to the suppression of the electron-hole recombination at grain boundaries. In the diode analysis, the facilitated phase formation suppressed the shunt path, decreasing the values of the diode factor (A), shunt conductance (G), and saturated current (J(o)), thereby improving the cell performance. In this study, ACIGS solar cells with an efficiency of 7.21% prepared via the nonvacuum process were first demonstrated.