Küllmey Tim, Hein Jakob, Heppke Eva M, Efthimiopoulos Ilias, Paulus Beate
Institut für Chemie und Biochemie, Freie Universität Berlin, Arnimallee 22, 14195 Berlin, Germany.
Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 135, 10623 Berlin, Germany.
ACS Omega. 2021 Oct 8;6(41):27387-27395. doi: 10.1021/acsomega.1c04290. eCollection 2021 Oct 19.
We carried out first-principles calculations to simulate AgZnSnS and AgCdSnS and calculated enthalpies of different plausible structural models (kesterite-type, stannite-type, wurtzkesterite-type, wurtzstannite-type, and GeSb-type) to identify low- and high-pressure phases. For AgZnSnS, we predict the following transition: kesterite-type→[8.2GPa]→ GeSb-type. At the transition pressure, the electronic structure changes from semiconducting to metallic. For AgCdSnS, we cannot decide which of the experimentally observed structures (kesterite-type or wurtzkesterite-type) is the ground-state structure because their energy difference is too small. At 4.7 GPa, however, we predict a transition to the GeSb-type structure with metallic character for both structures. Regarding the sensitivity of the material to disorder, a major drawback for solar cell applications, AgCdSnS behaves similar to CuZnSnS, both showing a high tendency to cationic disorder. In contrast, the disordered structures in AgZnSnS are much higher in energy, and therefore, the material is less affected by disorder.
我们进行了第一性原理计算来模拟AgZnSnS和AgCdSnS，并计算了不同可能结构模型（纤锌矿型、黄锡矿型、纤锌黄锡矿型、纤锌黄锡矿型和GeSb型）的焓，以确定低压和高压相。对于AgZnSnS，我们预测了以下转变：纤锌矿型→[8.2吉帕斯卡]→GeSb型。在转变压力下，电子结构从半导体变为金属。对于AgCdSnS，我们无法确定实验观察到的结构（纤锌矿型或纤锌黄锡矿型）中哪一个是基态结构，因为它们的能量差太小。然而，在4.7吉帕斯卡时，我们预测这两种结构都会转变为具有金属特性的GeSb型结构。关于材料对无序的敏感性，这是太阳能电池应用的一个主要缺点，AgCdSnS的行为与CuZnSnS相似，两者都表现出高阳离子无序倾向。相比之下，AgZnSnS中的无序结构能量要高得多，因此，该材料受无序影响较小。
