Scholarlink

<p>Lead-free double halide perovskites, specifically Cs₂TlAX₆ (A = As, Sb; X = Cl, Br, I), offer key advantages over lead-based versions, including strong optical absorption, high structural and thermal stability, superior carrier mobility, tunable band gaps, non-toxicity, and cost-effectiveness. Their mechanical, electrical, optical, and thermal properties were investigated using DFT with the PBE functional under ambient and hydrostatic pressures. Stability was confirmed through formation enthalpy, tolerance factor, and elastic constants. Pugh’s and Poisson’s ratios suggest these compounds are generally ductile (except Cs₂TlAsBr₆), with pressure-enhanced machinability, reduced friction, and increased plastic strain. Band structure analysis using the GGA-PBE approximation shows the direct band gap semiconducting nature of Cs₂TlAX₆ (A = As, Sb; X = Cl, Br, I), where the band gap values are ranging from 0.957 to 1.697&#xa0;eV. However, the TB-mBJ functional efficiently moderates the GGA-PBE underestimation, yielding refined band gaps between 1.22 and 2.17&#xa0;eV—values which are more efficient solar applications. Pressure-induced band gap tuning highlights potential for optoelectronic device applications. Their narrow band gaps and strong absorption make them suitable for solar cells, while high infrared reflectivity and low thermal conductivity indicate potential as thermal barrier coatings (TBCs).</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Ab-initio study of the structural, mechanical, electronic, optical, and thermal characteristics of lead-free double perovskites Cs₂TlAX₆ (A = As, Sb; X = Cl, Br, I) under hydrostatic pressure

  • 期刊论文

  • 发表日期：

    2026年1月10日

查看全文
  • Md. Atikur Rahman,
  • Ahmad Irfan,
  • Md. Nadim Mahamud Nobin,
  • Mst. Asma Khatun,
  • Md. Ferdous Rahman

摘要

Lead-free double halide perovskites, specifically Cs₂TlAX₆ (A = As, Sb; X = Cl, Br, I), offer key advantages over lead-based versions, including strong optical absorption, high structural and thermal stability, superior carrier mobility, tunable band gaps, non-toxicity, and cost-effectiveness. Their mechanical, electrical, optical, and thermal properties were investigated using DFT with the PBE functional under ambient and hydrostatic pressures. Stability was confirmed through formation enthalpy, tolerance factor, and elastic constants. Pugh’s and Poisson’s ratios suggest these compounds are generally ductile (except Cs₂TlAsBr₆), with pressure-enhanced machinability, reduced friction, and increased plastic strain. Band structure analysis using the GGA-PBE approximation shows the direct band gap semiconducting nature of Cs₂TlAX₆ (A = As, Sb; X = Cl, Br, I), where the band gap values are ranging from 0.957 to 1.697 eV. However, the TB-mBJ functional efficiently moderates the GGA-PBE underestimation, yielding refined band gaps between 1.22 and 2.17 eV—values which are more efficient solar applications. Pressure-induced band gap tuning highlights potential for optoelectronic device applications. Their narrow band gaps and strong absorption make them suitable for solar cells, while high infrared reflectivity and low thermal conductivity indicate potential as thermal barrier coatings (TBCs).