Tong Chuan-Jia, McKenna Keith P
Department of Physics, University of York, Heslington, York YO10 5DD, United Kingdom.
J Phys Chem C Nanomater Interfaces. 2019 Oct 3;123(39):23882-23889. doi: 10.1021/acs.jpcc.9b08373. Epub 2019 Sep 12.
Using first-principles density functional calculations, we investigate the structure and properties of three different grain boundaries (GBs) in the solar absorber material CdTe. Among the low ∑ value symmetric tilt GBs ∑3 (111), ∑3 (112), and ∑5 (310), we confirm that the ∑3 (111) is the most stable one but is relatively benign for carrier transport as it does not introduce any new states into the gap. The ∑3 (112) and ∑5 (310) GBs, however, are detrimental due to gap states induced by Te-Te and Cd-Cd dangling bonds. We systematically investigate the segregation of O, Se, Cl, Na, and Cu to the GBs and associated electronic properties. Our results show that co-doping with Cl and Na is predicted to be a viable approach passivating all gap states induced by dangling bonds in CdTe.
我们使用第一性原理密度泛函计算方法，研究了太阳能吸收材料碲化镉（CdTe）中三种不同晶界（GBs）的结构和性质。在低∑值对称倾斜晶界∑3(111)、∑3(112)和∑5(310)中，我们证实∑3(111)是最稳定的，但对载流子输运相对无害，因为它不会在能隙中引入任何新的态。然而，∑3(112)和∑5(310)晶界由于碲-碲和镉-镉悬键诱导的能隙态而有害。我们系统地研究了氧、硒、氯、钠和铜在晶界的偏析以及相关的电子性质。我们的结果表明，氯和钠的共掺杂预计是一种可行的方法，可以钝化碲化镉中由悬键诱导的所有能隙态。
