摘要
本工作提出了一种对Cu2ZnSnS4中Zn元素异价取代策略,探讨了新型四元硫族化合物A2M2M'Q4(A=Na,K,Rb,Cs,In,Tl;M=Cu,Ag,Au;M'=Ti,Zr,Hf,Ge,Sn;Q=S,Se,Te)作为新型太阳能电池吸收层材料的应用潜力.利用第一性原理高通量计算,评估了 1350种A2M2M'Q4化合物热力学稳定性、带隙、光谱极限最大效率和声子色散谱等特性.结果表明,有10种热力学和动力学稳定的候选材料,它们表现出合适的带隙,并展现出高的光吸收性能,光谱极限最大效率的理论值均超过30％.它们的电子结构和光学性质类似于Cu2ZnSnS4,有望应用于高效单结薄膜太阳能电池.本文数据集可在https://www.doi.org/10.57760/sciencedb.j00213.00006中访问获取.
Abstract
In recent decades,the demand for clean energy has promoted extensive research on solar cells as a key renewable energy source.Among the various emerging absorber layer materials,Kesterite-type semiconductors have aroused significant interest.Especially,Kesterite Cu2ZnSnS4(CZTS)stands out as a promising candidate for low-cost thin-film solar cells due to its direct bandgap,high optical absorption coefficient,suitable bandgap(1.39-1.52 eV),and abundance of constituent elements.However,the power conversion efficiency(PCE)of CZTS-based solar cells currently lags behind that of Cu(In,Ga)Se2(CIGS)cells,mainly due to insufficient open-circuit voltage caused by a large number of disordered cations and defect clusters,resulting in non-radiative recombination and band-tail states.To address these challenges,partial or complete cation substitution has become a viable strategy for altering the harmful defects in CZTS.This study proposes a heterovalent substitution of Zn in CZTS and explores the potential of novel quaternary chalcogenide compound A2M2M'Q4(A=Na,K,Rb,Cs,In,Tl;M=Cu,Ag,Au;M'=Ti,Zr,Hf,Ge,Sn;Q=S,Se,Te)as absorbers for solar cells.By substituting elements in five prototype structures,a comprehensive material database comprising 1350 A2M2M'Q4 compounds is established.High-throughput screening and first-principles calculations are used to evaluate the thermodynamic stabilities,band gaps,spectroscopic limited maximum efficiencies(SLMEs),and phonon dispersions of these compounds.Our research results indicate that 543 compounds exhibit thermodynamic stability(Ehull＜0.01 eV/atom),202 compounds possess suitable band gaps(1.0-1.5 eV),and 10 compounds meet all the criteria for thermodynamic and dynamic stability,suitable band gaps,and high optical absorption performance(104-106 cm-1),with theoretical SLME values exceeding 30％.Notably,Ibam-Rb2Ag2GeTe4 exhibits the highest SLME(31.8％)in these candidates,featuring a band gap of 1.27 eV and a small carrier effective mass(＜m0).The electronic structures and optical properties of these compounds are comparable to those of CZTS,which makes them suitable for highly efficient single-junction thin-film solar cells.All the data presented in this work can be found at https://www.doi.org/10.57760/sciencedb.j00213.00006.
维普
万方数据