A new selenide semiconductor NaMn3Ga3Se8 with strong second-harmonic generation and significant luminescence property

Multifunctional semiconductors play an important role in developing advanced photoelectric technologies. In this work, based on an octahedral replacement strategy in chalcogenides, a new selenide semiconductor NaMn 3 Ga 3 Se 8 was rationally designed, and synthesized by the flux method. The compound crystallizes in the noncentrosymmetric (NCS) P 6 ¯ space group, and is composed of unique prismatic [NaSe 6 ], octahedral [MnSe 6 ] and tetrahedral [GaSe 4 ] motifs, inheriting the stable three-dimensional framework built by the octahedral and tetrahedral units in the A I Mg 3 II C 3 III Q 8 VI family. NaMn 3 Ga 3 Se 8 shows the largest known secondary nonlinear optical (NLO) response of ∼2.1 × AgGaS 2 (AGS) in the A I Mg 3 II C 3 III Q 8 VI family, and a high laser-induced damage threshold of ∼3.0 × AGS. Meanwhile, the introduction of Mn 2+ with unpaired 3 d electrons induces a strong red emission band (685–805 nm) under the excitation source of 496 nm, as well as a paramagnetic to antiferromagnetic (AFM) transition at 7.3 K. The results confirm that NaMn 3 Ga 3 Se 8 possesses multifunctional features including significant NLO response, fluorescence emission and AFM properties, and illustrate that replacing octahedral units with approaching size and geometry (like [MgSe 6 ] and [MnSe 6 ]) could be a feasible way to develop multifunctional chalcogenides.