Since the polycrystalline (Cu₁-xAgx)₂ZnSnSe₄ (CAZTSe) demonstrated good optical absorption performance in the visible region, the focus of the present study is to grow the polycrystalline (Cu₁-xAgx)₂ZnSnSe₄ thin films deposited by thermal evaporation method on silicon substrates with 800 nm thickness and 0.53 nm/sec deposition rate as a function of Ag content (0.0,0.1,0.2) and annealing temperature at 373 K, 473 K. From I-V measurements of Al/n-CdS/p-CAZTSe/n-Si(111)/Al heterojunction solar cells under dark and illumination conditions, we observed that the forward bias current changes roughly exponentially with bias voltage and the ideality factor and saturation current dependence on both x content and different temperatures (Ta).