Carrier-density dependence of photoluminescence from localized states in InGaN/GaN quantum wells in nanocolumns and a thin film

AbstractWe have evaluated the optical gain of GaN/AlGaN quantum well structures with localized states, taking into account the Coulomb interaction. The localized states axe introduced in the well as quantum dot-like subband states. We have used the temperature Green's function formalism to treat the many-body effects and have found a new excitonic enhancement of the optical gain involved the localized states. This enhancement is stronger than the conventional Coulomb enhancement. It might play an important role to reduce the threshold carrier density.

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Optical properties of extended and localized states in m-plane InGaN quantum wells

Applied Physics Letters ◽

10.1063/1.4794904 ◽

2013 ◽

Vol 102 (10) ◽

pp. 101102 ◽

Cited By ~ 30

Author(s):

S. Marcinkevičius ◽

K. M. Kelchner ◽

S. Nakamura ◽

S. P. DenBaars ◽

J. S. Speck

Keyword(s):

Optical Properties ◽

Quantum Wells ◽

Localized States ◽

Ingan Quantum Wells

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A comparison of the carrier density at the surface of quantum wells for different crystal orientations of silicon, gallium arsenide, and indium arsenide

Applied Physics Letters ◽

10.1063/1.4825107 ◽

2013 ◽

Vol 103 (16) ◽

pp. 162107 ◽

Cited By ~ 2

Author(s):

Ryan Hatcher ◽

Chris Bowen

Keyword(s):

Gallium Arsenide ◽

Quantum Wells ◽

Indium Arsenide ◽

Carrier Density ◽

Crystal Orientations

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Carrier-density dependence of the activation energies associated with hopping in two-dimensional impurity bands

Philosophical Magazine B ◽

10.1080/13642818008245412 ◽

1980 ◽

Vol 41 (6) ◽

pp. 619-624 ◽

Cited By ~ 3

Author(s):

K. J. Hayden

Keyword(s):

Density Dependence ◽

Carrier Density ◽

Activation Energies ◽

Two Dimensional ◽

Impurity Bands

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Sol–gel synthesis and optical properties of titanium dioxide thin film

Modern Physics Letters B ◽

10.1142/s0217984918500768 ◽

2018 ◽

Vol 32 (09) ◽

pp. 1850076 ◽

Cited By ~ 3

Author(s):

Irfan Ullah ◽

Shaukat Ali Khattak ◽

Tanveer Ahmad ◽

Saman ◽

Nayab Ali Ludhi

Keyword(s):

Thin Film ◽

Titanium Dioxide ◽

Optical Properties ◽

Band Gap ◽

Surface Defects ◽

Sol Gel ◽

Luminescent Properties ◽

Localized States ◽

Indirect Transition ◽

Transmission And Absorption

The titanium dioxide (TiO2) is synthesized by sol–gel method using titanium-tetra-iso-propoxide (TTIP) as a starting material, and deposited on the pre-cleaned glass substrate using spin coating technique at optimized parameters. Energy dispersive X-ray (EDX) spectroscopy confirms successful TiO2 growth. The optical properties concerning the transmission and absorption spectra show 85% transparency and 3.28 eV wide optical band gap for indirect transition, calculated from absorbance. The exponential behavior of absorption edge is observed and attributed to the localized states electronic transitions, curtailed in the indirect band gap of the thin film. The film reveals decreasing refractive index with increasing wavelength. The photoluminescence (PL) study ascertains that luminescent properties are due to the surface defects.

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