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1. Phase transition in epitaxial bismuth nanofilms

   https://doi.org/10.1063/5.0016793  

   He, Feng; Walker, Emily S.; Zhou, Yongjian; Montano, Raul D.; Bank, Seth R.; Wang, Yaguo (August 2020, Applied Physics Letters)

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2. Band Topology of Bismuth Quantum Films

   https://doi.org/10.3390/cryst9100510  

   Chang, Tay-Rong; Lu, Qiangsheng; Wang, Xiaoxiong; Lin, Hsin; Miller, T.; Chiang, Tai-Chang; Bian, Guang (October 2019, Crystals)

   Bismuth has been the key element in the discovery and development of topological insulator materials. Previous theoretical studies indicated that Bi is topologically trivial and it can transform into the topological phase by alloying with Sb. However, recent high-resolution angle-resolved photoemission spectroscopy (ARPES) measurements strongly suggested a topological band structure in pure Bi, conflicting with the theoretical results. To address this issue, we studied the band structure of Bi and Sb films by ARPES and first-principles calculations. The quantum confinement effectively enlarges the energy gap in the band structure of Bi films and enables a direct visualization of the Z 2 topological invariant of Bi. We find that Bi quantum films in topologically trivial and nontrivial phases respond differently to surface perturbations. This way, we establish experimental criteria for detecting the band topology of Bi by spectroscopic methods. 

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3. The Thermoelectric Properties of Bismuth Telluride

   https://doi.org/10.1002/aelm.201800904  

   Witting, Ian T.; Chasapis, Thomas C.; Ricci, Francesco; Peters, Matthew; Heinz, Nicholas A.; Hautier, Geoffroy; Snyder, G. Jeffrey (April 2019, Advanced Electronic Materials)

   Abstract Bismuth telluride is the working material for most Peltier cooling devices and thermoelectric generators. This is because Bi₂Te₃(or more precisely its alloys with Sb₂Te₃for p‐type and Bi₂Se₃for n‐type material) has the highest thermoelectric figure of merit,zT, of any material around room temperature. Since thermoelectric technology will be greatly enhanced by improving Bi₂Te₃or finding a superior material, this review aims to identify and quantify the key material properties that make Bi₂Te₃such a good thermoelectric. The largezTcan be traced to the high band degeneracy, low effective mass, high carrier mobility, and relatively low lattice thermal conductivity, which all contribute to its remarkably high thermoelectric quality factor. Using literature data augmented with newer results, these material parameters are quantified, giving clear insight into the tailoring of the electronic band structure of Bi₂Te₃by alloying, or reducing thermal conductivity by nanostructuring. For example, this analysis clearly shows that the minority carrier excitation across the small bandgap significantly limits the thermoelectric performance of Bi₂Te₃, even at room temperature, showing that larger bandgap alloys are needed for higher temperature operation. Such effective material parameters can also be used for benchmarking future improvements in Bi₂Te₃or new replacement materials. 

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4. Electrochemical Sensing of Hydrogen Peroxide Using Composite Bismuth Oxide/Bismuth Oxyselenide Nanostructures: Antagonistic Influence of Tungsten Doping

   https://doi.org/10.3390/electrochem5040030  

   Walimbe, Pooja D; Kumar, Rajeev; Shringi, Amit Kumar; Keelson, Obed; Ouma, Hazel Achieng; Yan, Fei (December 2024, Electrochem)

   This study investigates the underlying mechanisms of hydrogen peroxide (H₂O₂) sensing using a composite material of bismuth oxide and bismuth oxyselenide (Bi2OxSey). The antagonistic effect of tungsten (W)-doping on the electrochemical behavior was also examined. Undoped, 2 mol%, 4 mol%, and 6 mol% W-doped Bi2OxSey nanostructures were synthesized using a one-pot solution phase method involving selenium powder and hydrazine hydrate. W-doping induced a morphological transformation from nanosheets to spherical nanoparticles and amorphization of the bismuth oxyselenide phase. Electrochemical sensing measurements were conducted using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). H₂O₂ detection was achieved over a wide concentration range of 0.02 to 410 µM. In-depth CV analysis revealed the complex interplay of oxidation-reduction processes within the bismuth oxide and Bi2O2Se components of the composite material. W-doping exhibited an antagonistic effect, significantly reducing sensitivity. Among the studied samples, undoped Bi2OxSeγ demonstrated a high sensitivity of 83 μA μM⁻1 cm⁻2 for the CV oxidation peak at 0 V, while 6 mol% W-Bi2OxSey became completely insensitive to H2O2. Interestingly, DPV analysis showed a reversal of sensitivity trends with 2 and 4 mol% W-doping. The applicability of these samples for real-world analysis, including rainwater and urine, was also demonstrated. 

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5. A Multidimensional Approach to Carbodiphosphorane–Bismuth Coordination Chemistry: Cationization, Redox-Flexibility, and Stabilization of a Crystalline Bismuth Hydridoborate

   https://doi.org/10.1021/acs.inorgchem.2c03337  

   Obi, Akachukwu D.; Dickie, Diane A.; Tiznado, William; Frenking, Gernot; Pan, Sudip; Gilliard, Robert J. (December 2022, Inorganic Chemistry)