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1. Investigation of n-type doping strategies for Mg ₃ Sb ₂

   https://doi.org/10.1039/c8ta03344g  

   Gorai, Prashun; Ortiz, Brenden R.; Toberer, Eric S.; Stevanović, Vladan (January 2018, Journal of Materials Chemistry A)

   Recent, and somewhat surprising, successful n-type doping of Mg 3 Sb 2 was the key to realizing high thermoelectric performance in this material. Herein, we use first-principles defect calculations to investigate different extrinsic n-type doping strategies for Mg 3 Sb 2 and to reveal general chemical trends in terms of dopant solubilities and maximal achievable electron concentrations. In agreement with experiments, we find that Sb substitution is an effective doping strategy, with Se and Te doping predicted to yield up to ∼8 × 10 19 cm −3 electrons. However, we also find that Mg substitution with trivalent (or higher) cations can be even more effective; in particular, the predicted highest achievable electron concentration (∼5 × 10 20 cm −3 ) with La as an extrinsic dopant exceeds that of Se and Te doping. Interstitial doping (Li, Zn, Cu, Be) is found to be largely ineffective either due to self-compensation (Li) or high formation energy (Zn, Cu, Be). Our results offer La as an alternative dopant to Te and Se and reinforce the need for careful phase boundary mapping in achieving high electron concentrations in Mg 3 Sb 2 . 

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2. Al Composition Dependence of Band Offsets for SiO ₂ on α-(Al _x Ga _1−x ) ₂ O ₃

   https://doi.org/10.1149/2162-8777/ac39a8  

   Xia, Xinyi; Fares, Chaker; Ren, Fan; Hassa, Anna; von Wenckstern, Holger; Grundmann, Marius; Pearton, S. J. (November 2021, ECS Journal of Solid State Science and Technology)

   Valence band offsets for SiO 2 deposited by Atomic Layer Deposition on α -(Al x Ga 1-x ) 2 O 3 alloys with x = 0.26–0.74 were measured by X-ray Photoelectron Spectroscopy. The samples were grown with a continuous composition spread to enable investigations of the band alignment as a function of the alloy composition. From measurement of the core levels in the alloys, the bandgaps were determined to range from 5.8 eV (x = 0.26) to 7 eV (x = 0.74). These are consistent with previous measurements by transmission spectroscopy. The valence band offsets of SiO 2 with these alloys of different composition were, respectively, were −1.2 eV for x = 0.26, −0.2 eV for x = 0.42, 0.2 eV for x = 0.58 and 0.4 eV for x = 0.74. All of these band offsets are too low for most device applications. Given the bandgap of the SiO 2 was 8.7 eV, this led to conduction band offsets of 4.1 eV (x = 0.26) to 1.3 eV (x = 0.74). The band alignments were of the desired nested configuration for x > 0.5, but at lower Al contents the conduction band offsets were negative, with a staggered band alignment. This shows the challenge of finding appropriate dielectrics for this ultra-wide bandgap semiconductor system. 

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3. Surface Defect Engineering of MoS ₂ for Atomic Layer Deposition of TiO ₂ Films

   https://doi.org/10.1021/acsami.0c13095  

   Kropp, Jaron A.; Sharma, Ankit; Zhu, Wenjuan; Ataca, Can; Gougousi, Theodosia (October 2020, ACS Applied Materials & Interfaces)

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4. Needleless Electrospinning for High Throughput Production of Li ₇ La ₃ Zr ₂ O ₁₂ Solid Electrolyte Nanofibers

   https://doi.org/10.1021/acs.iecr.9b03376  

   Rosenthal, Tanner; Weller, J. Mark; Chan, Candace K. (September 2019, Industrial & Engineering Chemistry Research)
5. Role of Lithium Doping in P2-Na _0.67 Ni _0.33 Mn _0.67 O ₂ for Sodium-Ion Batteries

   https://doi.org/10.1021/acs.chemmater.1c00569  

   Xie, Yingying; Gabriel, Eric; Fan, Longlong; Hwang, Inhui; Li, Xiang; Zhu, Haoyu; Ren, Yang; Sun, Chengjun; Pipkin, Julie; Dustin, Malia; et al (June 2021, Chemistry of Materials)