Heterogeneity of grain boundary properties in Cu2ZnSnS4: A first-principles study
Heterogeneity of grain boundary properties in Cu2ZnSnS4: A first-principles study
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DOI：
10.1063/5.0147435
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发表时间：
2023-04
影响因子：
3.2
通讯作者：
N. Hao;Rui-Xue Ding;C. Tong;K. McKenna
中科院分区：
文献类型：
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作者：
N. Hao;Rui-Xue Ding;C. Tong;K. McKenna
使用第一性原理密度泛函计算，我们研究了以前未研究的太阳能吸收材料铜锌锡硫化物（CZTS）的晶界（GB）的结构和性能。我们确定了四个稳定的低α值对称倾斜GB与低形成能：113（111）和115（201），每个有两个不同的GB终端。与CdTe和CuInSe相比，四元半导体CZTS中的GB表现出更广泛的电子状态，这是由于GB附近的化学环境更复杂，包括欠配位原子和悬挂键。进一步的分析证实，强悬挂键引入深隙态在所有的GB研究。我们还研究了本征点缺陷对GB的偏析和电子性质，发现其中一个113（111）GB表现出异常的缺陷偏析行为，有利于贫Cu（富Zn）GB成分，这对其整体性能有利。
Using first-principles density functional calculations, we investigate the structure and properties of previously unstudied grain boundaries (GBs) in the solar absorber material copper-zinc-tin-sulfide (CZTS). We identify four stable low-Σ value symmetric tilt GBs with low formation energies: Σ3 (111) and Σ5 (201), each with two different GB terminations. Compared to CdTe and CuInSe, GBs in the quaternary semiconductor CZTS exhibit a wider variety of electronic states due to the more complex chemical environment near the GB, including under-coordinated atoms and dangling bonds. Further analysis confirms that strong dangling bonds introduce deep gap states in all GBs studied. We also investigate segregation and electronic properties of intrinsic point defects to GBs and find that one of the Σ3 (111) GBs exhibits an abnormal defect segregation behavior that favors Cu-poor (Zn-rich) GB composition, which is beneficial for its overall performance.