Band‐Gap Engineering: Band‐Gap Engineering at a Semiconductor–Crystalline Oxide Interface (Adv. Mater. Interfaces 4/2015)

Jahangir-Moghadam, Mohammadreza; Ahmadi-Majlan, Kamyar; Droubay, Timothy C.; Bowden, Mark E.; Chrysler, Matthew; Su, Dong; Chambers, Scott A.; Ngai, J. H.

doi:10.1002/admi.201570020

Cited by 2 publications

(2 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[40] Substitution of Zr ions for Ti has been shown to produce a wide, tunable range of band gaps by removing low lying Ti 3d states. [39] Using this approach, it may be possible to raise the bottom of the conduction band to reduce free carrier concentrations and control the absorption energies induced by Fe 2+ dopants.…”

Section: Discussionmentioning

confidence: 99%

Infrared optical absorption in low-spin Fe²⁺-doped SrTiO₃

Comès

Kaspar

Heald

et al. 2016

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

Band gap engineering in SrTiO3 and related titanate perovskites has long been explored due to the intriguing properties of the materials for photocatalysis and photovoltaic applications. A popular approach in the materials chemistry community is to substitutionally dope aliovalent transition metal ions onto the B site in the lattice to alter the valence band. However, in such a scheme there is limited control over the dopant valence, and compensating defects often form. Here we demonstrate a novel technique to controllably synthesize Fe(2+)- and Fe(3+)-doped SrTiO3 thin films without formation of compensating defects by co-doping with La(3+) ions on the A site. We stabilize Fe(2+)-doped films by doping with two La ions for every Fe dopant, and find that the Fe ions exhibit a low-spin electronic configuration, producing optical transitions in the near infrared regime and degenerate doping. The novel electronic states observed here offer a new avenue for band gap engineering in perovskites for photocatalytic and photovoltaic applications.

show abstract

Section: Discussionmentioning

confidence: 99%

Infrared optical absorption in low-spin Fe²⁺-doped SrTiO₃

Comès

Kaspar

Heald

et al. 2016

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

show abstract

“…The creation of localized states through doping with nonisovalent ions has been shown to be an effective route in reducing the band gap − but comes at the cost of a decrease of energy conversion efficiency through charge trapping. Alloying − or codoping are alternative approaches that are generally less critical in terms of trap state creation but are more complex or limited to the specific material system. As band structures of oxide semiconductors are often particularly sensitive to changes in bond angles and bond length, strain has been suggested as a general means to tailor band alignments without the introduction of trap sites. − Practically, strain in thin films is usually imposed by the heteroepitaxial growth on nonlattice-matched substrates.…”

mentioning

confidence: 99%

Continuously Controlled Optical Band Gap in Oxide Semiconductor Thin Films

2016

View full text Add to dashboard Cite

The optical band gap of the prototypical semiconducting oxide SnO2 is shown to be continuously controlled through single axis lattice expansion of nanometric films induced by low-energy helium implantation. While traditional epitaxy-induced strain results in Poisson driven multidirectional lattice changes shown to only allow discrete increases in bandgap, we find that a downward shift in the band gap can be linearly dictated as a function of out-of-plane lattice expansion. Our experimental observations closely match density functional theory that demonstrates that uniaxial strain provides a fundamentally different effect on the band structure than traditional epitaxy-induced multiaxes strain effects. Charge density calculations further support these findings and provide evidence that uniaxial strain can be used to drive orbital hybridization inaccessible with traditional strain engineering techniques.

show abstract

Band‐Gap Engineering: Band‐Gap Engineering at a Semiconductor–Crystalline Oxide Interface (Adv. Mater. Interfaces 4/2015)

Abstract: In article 1400497, J. H. Ngai and co‐workers demonstrate that the band offset between single crystalline SrZrxTi1−xO3 and Ge can be tuned through the Zr content, providing a pathway to control electrical coupling between multifunctional oxides and semiconductors.

Cited by 2 publications

References 0 publications

Infrared optical absorption in low-spin Fe²⁺-doped SrTiO₃

Infrared optical absorption in low-spin Fe²⁺-doped SrTiO₃

Continuously Controlled Optical Band Gap in Oxide Semiconductor Thin Films

Contact Info

Product

Resources

About

Band‐Gap Engineering: Band‐Gap Engineering at a Semiconductor–Crystalline Oxide Interface (Adv. Mater. Interfaces 4/2015)

Abstract: In article 1400497, J. H. Ngai and co‐workers demonstrate that the band offset between single crystalline SrZrxTi1−xO3 and Ge can be tuned through the Zr content, providing a pathway to control electrical coupling between multifunctional oxides and semiconductors.

Cited by 2 publications

References 0 publications

Infrared optical absorption in low-spin Fe2+-doped SrTiO3

Infrared optical absorption in low-spin Fe2+-doped SrTiO3

Continuously Controlled Optical Band Gap in Oxide Semiconductor Thin Films

Contact Info

Product

Resources

About

Infrared optical absorption in low-spin Fe²⁺-doped SrTiO₃

Infrared optical absorption in low-spin Fe²⁺-doped SrTiO₃