第一性原理研究锌黄锡矿以外的CZTS拉曼光谱
CZTS Raman spectra beyond kesterite: a first-principles study
摘要：
Cu $_2$ ZnSnS $_4$是一种地球上丰富的光伏吸收材料，预计将为商业太阳能应用提供可持续的解决方案。限制其商业化的主要限制之一是阳离子紊乱问题。拉曼光谱技术一直是一个寻求后的技术来表征无序的CZTS，而理论和实验结果之间的明确共识尚未实现。在本研究中，通过虚晶近似，我们考虑到在CZTS中的Cu-Zn无序的渐进性质：我们得到的声子频率在带中心内的密度泛函微扰理论的形式主义，并进一步计算的拉曼光谱的无序相，实现理论和实验之间的共识。这些计算证实了在Cu-Zn 2 $a$、2 $c$和2 $d$ Wyckoff位点中存在完全无序。他们还表明，拉曼强度的两个突出的$A$声子模式，其特征在于运动的S原子，也被称为是实验上显着的，在理解的性质的无序CZTS中发挥了关键作用。
英文摘要：
Cu$_2$ZnSnS$_4$ is an earth-abundant photovoltaic absorber material predicted to provide a sustainable solution for commercial solar applications. One of the main limitations restricting its commercialization is the issue of cation disorder. Raman spectroscopy has been a sought after technique to characterize disorder in CZTS while a clear consensus between theoretical and experimental results is yet to be achieved. In the present study, via the virtual crystal approximation, we take into account the progressive nature of Cu-Zn disorder in CZTS: we obtain the phonon frequencies at zone-center within the density functional perturbation theory formalism, and further compute the Raman spectra for the disordered phases, achieving a consensus between theory and experiment. These calculations confirm the presence of complete disorder in Cu-Zn 2$a$, 2$c$ and 2$d$ Wyckoff sites. They also show that the Raman intensities of two prominent $A$ phonon modes characterized by motion of S atoms, also known to be experimentally significant, play a key role in understanding the nature of disorder in CZTS.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
