Electronic spectral parameters and IR nonlinear optical features of novel Ag0.5Pb1.75GeS4 crystal

► Novel Ag0.5Pb1.75GeS4 crystals were synthesized. ► A dramatic decrease of the relative intensity of the XPS C 1s core-level spectrum of the crystal surface after Ar+ ion-bombardment was found. ► Strong enhancement of photoinduced SHG output efficiencies with temperature increment is observed.