研究目的
To investigate transparent conducting properties of In4Sn3O12 related compounds, including undoped and M-doped variants, to understand their structure, optical, and electrical properties.
研究成果
The study successfully synthesized and characterized undoped and M-doped In4Sn3O12 compounds. The major charge carriers are electrons from oxygen vacancies, as evidenced by increased conductivity after N2 annealing. DFT calculations show that substitutions do not significantly alter band structure or carrier mobility, but Sb lowers oxygen vacancy formation energy, potentially explaining lower resistivity. The nature of donor states is crucial for electrical conduction.
研究不足
Only the composition with x=0.5 for M-doped samples could be achieved without impurity; other compositions had impurities. Attempts to prepare Sb-substituted samples were not successful due to impurity phases. The DFT calculations underestimate the band gap energy compared to experimental values due to the use of approximate exchange-correlation functional.
1：Experimental Design and Method Selection:
The study uses solid-state reaction for synthesis, with phase purity confirmed by powder X-ray diffraction (XRD). Rietveld refinement is employed for crystallographic information. X-ray photoelectron spectroscopy (XPS) is used to identify oxidation states. Optical properties are probed by UV-Vis diffuse reflectance spectroscopy and photoluminescence (PL) spectroscopy. Electrical conductivity is measured by a four-probe technique. Density functional theory (DFT) calculations are used to investigate electronic band structure and oxygen vacancy formation energy.
2：Sample Selection and Data Sources:
Polycrystalline samples of In4Sn3O12 and doped variants (M = Nb, Ta) are synthesized. High-purity precursors include In2O3, SnO2, Sb2O3, Nb2O5, Ta2O5, Sc2O3, and ZrO
3：List of Experimental Equipment and Materials:
Equipment includes a Bruker D2 Phaser diffractometer for XRD, PHI5000 VersaProbe II for XPS, Agilent UV-Vis-NIR spectrophotometer (model Cary 5000) for DRS, AVANTES AvaSpec-2048TEC-USB2-2 spectrometer for PL, and a four-probe setup for electrical measurements. Materials are the chemical precursors listed.
4：Experimental Procedures and Operational Workflow:
Synthesis is performed at 1400-1450°C in air for 24-36 h with intermediate grindings. Annealing in N2 at 900°C for 3 h is done to study electrical property changes. XRD patterns are collected in the 2-theta range of 10-120° with an increment of 0.02° and a scan rate of 2s/step. XPS uses monochromatic Al Kα radiation. DRS collects spectra from 200-800 nm. PL uses a 255 nm excitation LED.
5：02° and a scan rate of 2s/step. XPS uses monochromatic Al Kα radiation. DRS collects spectra from 200-800 nm. PL uses a 255 nm excitation LED.
Data Analysis Methods:
5. Data Analysis Methods: Rietveld refinement with TOPAS software (V4.2.0.2) for XRD data. Kubelka-Munk function for band gap calculation from DRS data. DFT calculations using VASP 5.3 with PBE functional and PAW method for electronic structure analysis.
独家科研数据包，助您复现前沿成果，加速创新突破
获取完整内容
