Browsing by Author "Noe, G.T."

Now showing 1 - 3 of 3
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    Impact of growth temperature on InAs/GaInSb strained layer superlattices for very long wavelength infrared detection
    (American Institute of Physics, 2012-10-23) Haugan, H.J.; Brown, G.J.; Elhamri, S.; Mitchel, W.C.; Mahalingam, K.; Kim, M.; Noe, G.T.; Ogden, N.E.; Kono, J.
    We explore the optimum growth space for a 47.0A ° InAs/21.5A ° Ga0.75In0.25Sb superlattices (SLs) designed for the maximum Auger suppression for a very long wavelength infrared gap. Our growth process produces a consistent gap of 5065meV. However, SL quality is sensitive to the growth temperature (Tg). For the SLs grown at 390 470 C, a photoresponse signal gradually increases as Tg increases from 400 to 440 C. Outside this temperature window, the SL quality deteriorates very rapidly. All SLs were n-type with mobility of 10 000 V/cm2 and 300K recombination lifetime of 70 ns for an optimized SL
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    Renormalized energies of superfluorescent bursts from an electron-hole magnetoplasma with high gain in InxGa1−xAs quantum wells
    (American Physical Society, 2013) Kim, J.-H.; Lee, J.; Noe, G.T.; Wang, Y.; Wojcik, A.K.; McGill, S.A.; Reitze, D.H.; Belyanin, A.A.; Kono, J.
    We study light emission properties of a population-inverted 2D electron-hole plasma in a quantizing magnetic field. We observe a series of superfluorescent (SF) bursts, discrete both in time and energy, corresponding to the cooperative recombination of electron-hole pairs from different Landau levels. Emission energies exhibit strong renormalization due to many-body interactions among the photogenerated carriers, showing pronounced red shifts as large as 20 meV at 15 T. However, the lowest Landau level emission line remains stable against renormalization and show excitonic magnetic field dependence. Interestingly, our time-resolved measurements show that this lowest-energy SF burst occurs only after most upper states become empty, suggesting that this excitonic stability is related to the “hidden symmetry” of 2D magnetoexcitons expected in the magnetic quantum Limit.
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    Scaling law for excitons in 2D perovskite quantum wells
    (Springer Nature, 2018) Blancon, J.-C.; Stier, A.V.; Tsai, H.; Nie, W.; Stoumpos, C.C.; Traoré, B.; Pedesseau, L.; Kepenekian, M.; Katsutani, F.; Noe, G.T.; Kono, J.; Tretiak, S.; Crooker, S.A.; Katan, C.; Kanatzidis, M.G.; Crochet, J.J.; Even, J.; Mohite, A.D.
    Ruddlesden-Popper halide perovskites are 2D solution-processed quantum wells with a general formula A2A'n-1M n X3n+1, where optoelectronic properties can be tuned by varying the perovskite layer thickness (n-value), and have recently emerged as efficient semiconductors with technologically relevant stability. However, fundamental questions concerning the nature of optical resonances (excitons or free carriers) and the exciton reduced mass, and their scaling with quantum well thickness, which are critical for designing efficient optoelectronic devices, remain unresolved. Here, using optical spectroscopy and 60-Tesla magneto-absorption supported by modeling, we unambiguously demonstrate that the optical resonances arise from tightly bound excitons with both exciton reduced masses and binding energies decreasing, respectively, from 0.221 m0 to 0.186 m0 and from 470 meV to 125 meV with increasing thickness from n equals 1 to 5. Based on this study we propose a general scaling law to determine the binding energy of excitons in perovskite quantum wells of any layer thickness.