SrZn2N2 as a Solar Absorber: Theoretical Defect Chemistry and Synthesis by Metal Alloy Nitridation
SrZn2N2 as a Solar Absorber: Theoretical Defect Chemistry and Synthesis by Metal Alloy Nitridation
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SrZn2N2 作为太阳能吸收剂：理论缺陷化学和金属合金氮化合成
DOI：
10.1021/acs.chemmater.1c00075
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发表时间：
2021
影响因子：
8.6
通讯作者：
Oba Fumiyasu
中科院分区：
文献类型：
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作者：
Kikuchi Ryosuke;Ueno Koki;Nakamura Toru;Kurabuchi Takahiro;Kaneko Yasushi;Kumagai Yu;Oba Fumiyasu
三元锌氮化物CaZn2N2和SrZn2N2是一种很有前途的太阳能转换材料，因为它们的直接带隙可以调节到最佳值，并且它们只含有地球上丰富的元素。我们报告的第一性原理计算，重点是缺陷化学，并提出了一种合成SrZn2N2的方法。计算结果表明，虽然N空位在SrZn2N2中的形成能相对较低，且在带隙内表现出深能级，但通过控制晶体生长和非本征掺杂可以有效降低N空位的浓度.在600 °C和常压下，通过NH3氮化SrZn2合金制备SrZn2N2粉末。我们实验确定SrZn2N2的直接带隙为1.6 eV，与我们的理论预测一致。
The ternary zinc nitrides CaZn2N2and SrZn2N2are promising materials for solar energy conversion because their direct band gaps are tunable to optimal values, and they contain only earth-abundant elements. We report first-principles calculations with a focus on defect chemistry and propose a method of synthesis for SrZn2N2. Our calculations reveal that although the N vacancy has a relatively low formation energy among the native defects in SrZn2N2and shows deep levels within the band gap, its concentration can be sufficiently reduced by controlled crystal growth and extrinsic doping. The SrZn2N2powder was synthesized by NH3nitridation of the SrZn2alloy at 600 °C and atmospheric pressure. We experimentally determined the direct band gap of SrZn2N2to be 1.6 eV, consistent with our theoretical prediction.