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Band gap

About: Band gap is a(n) research topic. Over the lifetime, 86889 publication(s) have been published within this topic receiving 2242479 citation(s). The topic is also known as: bandgap & forbidden band. more


Open accessJournal ArticleDOI: 10.1126/SCIENCE.271.5251.933
A. P. Alivisatos1Institutions (1)
16 Feb 1996-Science
Abstract: Current research into semiconductor clusters is focused on the properties of quantum dots-fragments of semiconductor consisting of hundreds to many thousands of atoms-with the bulk bonding geometry and with surface states eliminated by enclosure in a material that has a larger band gap. Quantum dots exhibit strongly size-dependent optical and electrical properties. The ability to join the dots into complex assemblies creates many opportunities for scientific discovery. more

Topics: Quantum dot (62%), Superlattice (54%), Semiconductor (52%) more

10,373 Citations

Journal ArticleDOI: 10.1126/SCIENCE.1228604
02 Nov 2012-Science
Abstract: The energy costs associated with separating tightly bound excitons (photoinduced electron-hole pairs) and extracting free charges from highly disordered low-mobility networks represent fundamental losses for many low-cost photovoltaic technologies. We report a low-cost, solution-processable solar cell, based on a highly crystalline perovskite absorber with intense visible to near-infrared absorptivity, that has a power conversion efficiency of 10.9% in a single-junction device under simulated full sunlight. This "meso-superstructured solar cell" exhibits exceptionally few fundamental energy losses; it can generate open-circuit photovoltages of more than 1.1 volts, despite the relatively narrow absorber band gap of 1.55 electron volts. The functionality arises from the use of mesoporous alumina as an inert scaffold that structures the absorber and forces electrons to reside in and be transported through the perovskite. more

Topics: Perovskite solar cell (61%), Hybrid solar cell (58%), Solar cell (58%) more

7,996 Citations

Journal ArticleDOI: 10.1063/1.103561
Abstract: Indirect evidence is presented that free‐standing Si quantum wires can be fabricated without the use of epitaxial deposition or lithography. The novel approach uses electrochemical and chemical dissolution steps to define networks of isolated wires out of bulk wafers. Mesoporous Si layers of high porosity exhibit visible (red) photoluminescence at room temperature, observable with the naked eye under <1 mW unfocused (<0.1 W cm−2) green or blue laser line excitation. This is attributed to dramatic two‐dimensional quantum size effects which can produce emission far above the band gap of bulk crystalline Si. more

Topics: Quantum wire (55%), Band gap (53%), Silicon (53%) more

7,284 Citations

Journal ArticleDOI: 10.1021/NL903868W
Andrea Splendiani1, Liang Sun1, Yuanbo Zhang1, Tianshu Li2  +5 moreInstitutions (3)
15 Mar 2010-Nano Letters
Abstract: Novel physical phenomena can emerge in low-dimensional nanomaterials. Bulk MoS2, a prototypical metal dichalcogenide, is an indirect bandgap semiconductor with negligible photoluminescence. When the MoS2 crystal is thinned to monolayer, however, a strong photoluminescence emerges, indicating an indirect to direct bandgap transition in this d-electron system. This observation shows that quantum confinement in layered d-electron materials like MoS2 provides new opportunities for engineering the electronic structure of matter at the nanoscale. more

Topics: Transition metal dichalcogenide monolayers (59%), Photoluminescence (55%), Monolayer (54%) more

6,781 Citations

Journal ArticleDOI: 10.1063/1.1368156
Abstract: We present a comprehensive, up-to-date compilation of band parameters for the technologically important III–V zinc blende and wurtzite compound semiconductors: GaAs, GaSb, GaP, GaN, AlAs, AlSb, AlP, AlN, InAs, InSb, InP, and InN, along with their ternary and quaternary alloys. Based on a review of the existing literature, complete and consistent parameter sets are given for all materials. Emphasizing the quantities required for band structure calculations, we tabulate the direct and indirect energy gaps, spin-orbit, and crystal-field splittings, alloy bowing parameters, effective masses for electrons, heavy, light, and split-off holes, Luttinger parameters, interband momentum matrix elements, and deformation potentials, including temperature and alloy-composition dependences where available. Heterostructure band offsets are also given, on an absolute scale that allows any material to be aligned relative to any other. more

Topics: Band gap (61%), Heterojunction (57%), Effective mass (solid-state physics) (54%) more

5,816 Citations

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Topic's top 5 most impactful authors

Ali H. Reshak

146 papers, 2.3K citations

Wladek Walukiewicz

138 papers, 9.7K citations

Rabah Khenata

110 papers, 1.6K citations

Su-Huai Wei

105 papers, 9.4K citations

Kin Man Yu

101 papers, 6.6K citations

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