We report large enhancement in piezoelectric response (d₃₃) of wurtzite-AlN by addition of Mg and TM (TM = Cr, Mo, W). The piezoelectric properties of wurtzite Mg_xTM_yAl_(1−x−y)N was calculated by using first-principles calculations. In the composition range of 0.25 ≦ x + y ≦ 0.5, MgMoAlN and MgWAlN exhibit higher d₃₃ values than MgCrAlN. Among them, MgWAlN exhibited the highest d₃₃, where the d₃₃ value was found to be 10 times higher than that of AlN (d₃₃ ≃ 5.3 pC/N), and 1.5 times higher than that of ScAlN (d₃₃ ≃ 30 pC/N). We have also revealed that a higher elastic softening is the main contribution to the increase of d₃₃ in MgMoAlN and MgWAlN. From Bader charge analysis, Mg, Mo, and W have a lower charge than that of Al which indicate that the ionic bonding character is a weaker than Al. From crystal orbital Hamilton population analysis, covalent bonding between Mg–N and Mo/W–N are also found to be weaker than Al–N. Thus, a weaker ionic and covalent bonding are considered to play an important role in promoting elastic softening for MgMoAlN and MgWAlN, which eventually promoted significant enhancement in piezoelectricity.

我们报道通过添加Mg和TM（TM = Cr，Mo，W），纤锌矿型AlN的压电响应（d ₃₃）大大增强。通过使用第一性原理计算来计算纤锌矿Mg _x TM _y Al _{（1 -x-y）} N的压电性能。在 0.25≤x + y≤0.5的组成范围内，MgMoAlN和MgWAlN显示出比MgCrAlN更高的d ₃₃值。其中，MgWAlN表现出最高的d ₃₃，其中，所述d ₃₃值被发现是比的AlN（高10倍d ₃₃  ≃5.3 PC / N），和比ScAlN的1.5倍更高（d ₃₃  ≃30 PC / N）。我们还发现，较高的弹性软化是MgMoAlN和MgWAlN中d ₃₃增加的主要作用。根据Bader电荷分析，Mg，Mo和W的电荷比Al的电荷低，这表明离子键合特性比Al弱。根据汉密尔顿晶体轨道分析，Mg–N和Mo / W–N之间的共价键也弱于Al–N。因此，认为较弱的离子键和共价键在促进MgMoAlN和MgWAlN的弹性软化中起重要作用，从而最终促进了压电性的显着提高。