From CuFeS₂ to Ba₆Cu₂FeGe₄S₁₆: rational band gap engineering achieves large second-harmonic-generation together with high laser damage threshold

Abstract

From CuFeS2, the introduction of Ge leads to an increase in band gap. The ordered arrangement of NLO active units [GeS4] results in a strong SHG response. Finally, Ba6Cu2FeGe4S16 exhibits good NLO performance (SHG, 1.5 × AgGaSe2; LDT, 2 × AgGaSe2).

Melilite oxychalcogenide Sr2FeGe2OS6: a phase-matching IR nonlinear optical material realized by isomorphous substitution

“…2d). We compared the E g value with those of typical Fe-containing materials 31,32,[51][52][53][54][55][56][57][58][59][60][61][62][63] according to a detailed literature survey, as shown in Fig. 2e, and found that Sr 2 FeGe 2 OS 6 displays the largest E g among the 16 reported compounds based on experimental measurements.…”

Ba6(CuxZy)Sn4S16 (Z = Mg, Mn, Zn, Cd, In, Bi, Sn): High Chemical Flexibility Resulting in Good Nonlinear-Optical Properties

“…The Ba 6 (Cu x Z y )­Sn 4 S 16 (Z = Mg, Mn, Zn, Cd, In, Bi) compounds belong to the II 6 I 4 V 4 Ch 16 (II = Sr, Ba; I = Li, Cu, Ag; IV = Ge, Sn; Ch = S, Se) family. − A total of 30 compounds have been discovered in the II 6 I 4 V 4 Ch 16 family so far. − The number of compounds of the II 6 I 4 V 4 Ch 16 family was greatly expanded by introducing mixed occupancy at the Li/Cu/Ag atomic positions, where monovalent metals are replaced by divalent metals. The flexible combination of elements coupled with mixed occupancy at the Wyckoff position 12a accounts for a large number of compounds in the II 6 I 4 V 4 Ch 16 family.…”

“…), trivalent M 3+ (Al, In, Ga, etc. ), tetravalent M 4+ (Si, Ge, Sn), and pentavalent M 5+ (Sb); Ch = S, Se], which have demonstrated an excellent balance of NLO properties originating from their chemical flexibility. − Recently, another system, II 6 I 4 V 4 Ch 16 (II = Sr, Ba; I = Li, Cu, Ag; IV = Ge, Sn; Ch = S, Se), has been heavily studied because of their emerging NLO properties and the demonstration of their excellent chemical flexibility. − In this work, we discovered another seven compounds belonging to the II 6 I 4 V 4 Ch 16 (II = Sr, Ba; I = Li, Cu, Ag; IV = Ge, Sn; Ch = S, Se) family. The chemical flexibility of the II 6 I 4 V 4 Ch 16 (II = Sr, Ba; I = Li, Cu, Ag; IV = Ge, Sn; Ch = S, Se) family is further expanded on with the discovery of trivalent dopants for the first time.…”

AgGaGeSe4: An Infrared Nonlinear Quaternary Selenide with Good Performance

“…At present, many crystals can achieve frequency conversion in principle, but in fact, only few crystals, such as AgGaS 2 , AgGaSe 2, and ZnGeP 2 , are commercially mature [7][8][9]. Although the application of chalcopyrite infrared crystals has been promoted via the progress of high-quality crystal growth and processing technology, these infrared crystals still have shortcomings in terms of their properties, for instance, the low laser damage threshold of AgGaS 2 and AgGaSe 2 , the small band gap of AgGaSe 2 (1.79 eV), and the serious two-photon absorption of ZnGeP 2 [10][11][12]. All these existing problems limit their wide application.…”