Browsing by Subject "Electric field dependence"

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    Electric field dependence of radiative recombination lifetimes in polar InGaN/GaN quantum heterostructures
    (IEEE, 2009) Sarı, Emre; Nizamoğlu, Sedat; Lee I.-H.; Baek J.-H.; Demir, Hilmi Volkan
    We report on external electric field dependence of recombination lifetimes in polar InGaN/GaN quantum heterostructures. In our study, we apply external electric fields one order of magnitude less than and in opposite direction to the polarization-induced electrostatic fields inside the well layers. Under the increasing external electric field, we observe a decrease in carrier lifetimes (τ) and radiative recombination lifetimes (τr), latter showing a weaker dependence. Our results on τr show an agreement with our transfer matrix method based simulation results and demonstrate Fermi's golden rule in polar InGaN/GaN quantum heterostructures dependent on electric field. For our study, we grew 5 pairs of 2.5 nm thick In0.15Ga 0.85N quantum well and 7.5 nm thick GaN barrier layers in a p-i-n diode architecture using metal-organic chemical vapor deposition (MOCVD) on a c-plane sapphire substrate. Devices with 300 μm × 300 μm mesa size were fabricated using standard photolithography, reactive ion etching and metallization steps. We used indium-tin oxide (ITO) based semi-transparent contacts in top (p-GaN) layer for uniform application of electric field across the well layers. The fabricated devices were diced and mounted on a TO-can for compact testing. © 2009 IEEE.
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    Modulation of multilayer InAs quantum dot waveguides under applied electric field
    (Optical Society of America, 2007) Akça, Imran B.; Dana, Aykutlu; Aydınlı, Atilla; Rossetti, M.; Li L.; Fiore, A.; Dagli, N.
    Electric field dependence of optical modulation in self assembled InAs quantum dot waveguides have been studied at 1300 and 1500 nm. Electro-absorption and electro-optic coefficients of these waveguides have been obtained at both wavelengths. © 2007 Optical Society of America.