ORCID iDhttps://orcid.org/0000-0003-4784-6751

researchmap

著書/Books

  1. Energy Conversion Efficiency of Solar Cells
    T. Kita, Y. Harada, and S. Asahi
    (Springer, Singapore, 2019).

論文/Papers

  1. Output power-density limit of a thermoradiative diode with an intermediate band
    Y. Harada, F. Nishii, and T. Kita
    Scientific Reports 15, pp. 7452-1–11 (2025). Kobe University Repository Kernel

  2. The basic monochromatic photovoltaic properties of a photodiode for laser power conversion
    R. Hanakuma, S. Asahi, Y. Harada, and Takashi Kita
    Japanese Journal of Applied Physics 64, pp. 014001-1–5 (2025).

  3. Lateral photoconductivity of InAs/GaAs quantum dots for 1.5 μm-wavelength excitation photoconductive terahertz antenna devices
    T. Kaizu, O. Kojima, Y. Minami, T. Kitada, Y. Harada, T. Kita, and O. Wada
    Japanese Journal of Applied Physics 63, pp. 082002-1–5 (2024).

  4. 局在表面プラズモン共鳴による高密度ドープInAs/GaAs量子ドットにおける電場増強効果
    川上瑞人, 原田幸弘, 朝日重雄, 喜多隆
    材料 73, pp. 178–182 (2024).

  5. Two-step photon up-conversion solar cell using quantum dots embedded beneath the hetero-interface
    S. Asahi, Y. Harada, and T. Kita
    JSAP Review 2023, pp. 230426-1–5 (2023).

  6. Mechanism of THz dielectric constant enhancement in multi-component oxide glasses investigated by infrared and THz spectroscopies
    O. Wada, D. Ramachari, C.-S. Yang, Y. Harada, T. Uchino, and C.-L. Pan
    Journal of Physics and Chemistry of Solids 176, pp. 111237-1–14 (2023).

  7. Yb-doped Y–Al–O thin films with a self-organized columnar structure and their anti-Stokes photoluminescence properties
    Y. Nakayama, N. Nakagawa, Y. Matsuo, T. Kaizu, Y. Harada, T. Ishihara, and T. Kita
    AIP Advances 12, 025110-1–8 (2022). Kobe University Repository Kernel

  8. イッテルビウム添加イットリウムアルミニウムガーネット薄膜のアンチストークス発光特性と理想レーザー冷却性能
    中山雄太, 中川望夢, 原田幸弘, 喜多隆
    材料 69, pp. 727–732 (2020).

  9. Bandwidth enhancement in an InGaN/GaN three-section superluminescent diode for optical coherence tomography
    G. R. Goldberg, D.-H. Kim, R. J. E. Taylor, D. T. D. Childs, P. Ivanov, N. Ozaki, K. L. Kennedy, K. M. Groom, Y. Harada, and R. A. Hogg
    Applied Physics Letters 117, pp. 061106-1–5 (2020).

  10. An energy transfer accompanied by phonon absorption in ytterbium-doped yttrium aluminum perovskite for optical refrigeration
    Y. Nakayama, Y. Harada, and T. Kita
    Applied Physics Letters 117, pp. 041104-1–5 (2020). Kobe University Repository Kernel

  11. Bound-to-continuum intraband transition properties in InAs/GaAs quantum dot superlattice solar cells
    Y. Harada, S. Asahi, and T. Kita
    Applied Physics Express, 12, pp. 125008-1–4 (2019).

  12. Improving laser cooling efficiencies of Yb-doped yttrium aluminum garnet by utilizing non-resonant anti-Stokes emission at high temperatures
    Y. Nakayama, Y. Harada, and T. Kita
    Optics Express 27, pp. 34961–34973 (2019). Kobe University Repository Kernel

  13. Yb添加イットリウムアルミニウムガーネット結晶粉末におけるアンチストークス発光を利用した理想レーザー冷却効率
    中山雄太, 寺田康太, 原田幸弘, 喜多隆
    材料 68, pp. 762–766 (2019).

  14. Hot-carrier generation and extraction in InAs/GaAs quantum dot superlattice solar cells
    Y. Harada, N. Iwata, S. Asahi, and T. Kita
    Semiconductor Science and Technology 34, pp. 094003-1–5 (2019).

  15. Hot-carrier generation in a solar cell containing InAs/GaAs quantum-dot superlattices as a light absorber
    D. Watanabe, N. Iwata, S. Asahi, Y. Harada, and T. Kita
    Applied Physics Express 11, pp. 082303-1–4 (2018).

  16. Assessing the nature of the distribution of localised states in bulk GaAsBi
    T. Wilson, N. P. Hylton, Y. Harada, P. Pearce, D. Alonso-Álvarez, A. Mellor, R. D. Richards, J. P. R. David, and N. J. Ekins-Daukes
    Scientific Reports 8, pp. 6457-1–10 (2018). Kobe University Repository Kernel

  17. Increasing conversion efficiency of two-step photon up-conversion solar cell with a voltage booster hetero-interface
    S. Asahi, K. Kusaki, Y. Harada, and T. Kita
    Scientific Reports 8, pp. 872-1–8 (2018). Kobe University Repository Kernel

  18. Spatially resolved electronic structure of an isovalent nitrogen center in GaAs
    R. C. Plantenga, V. R. Kortan, T. Kaizu, Y. Harada, T. Kita, M. E. Flatté, and P. M. Koenraad
    Physical Review B 96, pp. 155210-1–8 (2017).

  19. InAs/GaAs量子ドット超格子を用いたホットキャリア型太陽電池の基礎特性
    渡部大樹, 原田幸弘, 喜多隆
    材料 66, pp. 629–633 (2017).

  20. Efficient two-step photocarrier generation in bias-controlled InAs/GaAs quantum dot superlattice intermediate-band solar cells
    T. Kada, S. Asahi, T. Kaizu, Y. Harada, R. Tamaki, Y. Okada, and T. Kita
    Scientific Reports 7, pp. 5865-1–10 (2017). Kobe University Repository Kernel

  21. Two-step photocurrent generation enhanced by miniband formation in InAs/GaAs quantum dot superlattice intermediate-band solar cells
    S. Watanabe, S. Asahi, T. Kada, K. Hirao, T. Kaizu, Y. Harada, and T. Kita
    Applied Physics Letters 110, pp. 193104-1–5 (2017). Kobe University Repository Kernel

  22. Photocarrier transport dynamics in InAs/GaAs quantum dot superlattice solar cells using time-of-flight spectroscopy
    T. Tanibuchi, T. Kada, S. Asahi, D. Watanabe, T. Kaizu, Y. Harada, and T. Kita
    Physical Review B 94, pp. 195313-1–9 (2016). Kobe University Repository Kernel

  23. Polarization characteristics of electroluminescence and net modal gain in highly stacked InAs/GaAs quantum-dot laser devices
    M. Suwa, T. Andachi, T. Kaizu, Y. Harada, and T. Kita
    Journal of Applied Physics 120, pp. 134313-1–6 (2016). Kobe University Repository Kernel

  24. Effects of rapid thermal annealing on two-dimensional delocalized electronic states of the epitaxial N δ-doped layer in GaAs
    Y. Ogawa, Y. Harada, T. Baba, T. Kaizu, and T. Kita
    Applied Physics Letters 108, pp. 111905-1–4 (2016). Kobe University Repository Kernel

  25. Nanosecond-scale hot-carrier cooling dynamics in one-dimensional quantum dot superlattices
    Y. Harada, N. Kasamatsu, D. Watanabe, and T. Kita
    Physical Review B 93, pp. 115303-1–5 (2016). Kobe University Repository Kernel

  26. 近接積層InAs/GaAs量子ドット半導体光アンプの光導波モード解析
    諏訪雅也, 大橋知幸, 安達貴哉, 海津利行, 原田幸弘, 喜多隆
    材料 64, pp. 685–689 (2015).

  27. Two-step photon absorption in InAs/GaAs quantum-dot superlattice solar cells
    T. Kada, S. Asahi, T. Kaizu, Y. Harada, T. Kita, R. Tamaki, Y. Okada, and K. Miyano
    Physical Review B 91, pp. 201303(R)-1–6 (2015). Kobe University Repository Kernel

  28. Thermal annealing effects on ultra-violet luminescence properties of Gd doped AlN
    T. Kita, Y. Ishizu, K. Tsuji, Y. Harada, Y. Chigi, T. Nishimoto, H. Tanaka, M. Kobayashi, T. Ishihara, and H. Izumi
    Journal of Applied Physics 117, pp. 163105-1–5 (2015). Kobe University Repository Kernel

  29. Hot-carrier solar cells using low-dimensional quantum structures
    D. Watanabe, N. Kasamatsu, Y. Harada, and T. Kita
    Applied Physics Letters 105, pp. 171904-1–5 (2014).

  30. Polarization-insensitive optical gain characteristics of highly stacked InAs/GaAs quantum dots
    T. Kita, M. Suwa, T. Kaizu, and Y. Harada
    Journal of Applied Physics 115, pp. 233512-1–5 (2014). Kobe University Repository Kernel

  31. Resonant indirect excitation of Gd3+ in AlN thin films
    Y. Ishizu, K. Tsuji, Y. Harada, T. Kita, Y. Chigi, T. Nishimoto, H. Tanaka, M. Kobayashi, T. Ishihara, and H. Izumi
    Journal of Applied Physics 115, pp. 173508-1–6 (2014).

  32. Effect of internal electric field on InAs/GaAs quantum dot solar cells
    N. Kasamatsu, T. Kada, A. Hasegawa, Y. Harada, and T. Kita
    Journal of Applied Physics 115, pp. 083510-1–5 (2014). Kobe University Repository Kernel

  33. Epitaxial two-dimensional nitrogen atomic sheet in GaAs
    Y. Harada, M. Yamamoto, T. Baba, and T. Kita
    Applied Physics Letters 104, pp. 041907-1–4 (2014). Kobe University Repository Kernel

  34. Polarization controlled emission from closely stacked InAs/GaAs quantum dots
    M. Suwa, A. Takahashi, T. Ueda, Y. Bessho, Y. Harada, and T. Kita
    Physica Status Solidi C 10, pp. 1492–1495 (2013).

  35. Control of stacking direction and optical anisotropy in InAs/GaAs quantum dots by In flux
    Y. Bessho, Y. Harada, T. Kita, E. Taguchi, and H. Yasuda
    Journal of Applied Physics 114, pp. 033517-1–5 (2013).

  36. One-dimensional miniband formation in closely stacked InAs/GaAs quantum dots
    A. Takahashi, T. Ueda, Y. Bessho, Y. Harada, T. Kita, E. Taguchi, and H. Yasuda
    Physical Review B 87, pp. 235323-1–6 (2013).

  37. Intraband carrier dynamics in InAs/GaAs quantum dots stimulated by bound-to-continuum excitation
    Y. Harada, T. Maeda, and T. Kita
    Journal of Applied Physics 113, pp. 223511-1–5 (2013). Kobe University Repository Kernel

  38. Intermediate band photovoltaic based on interband-intraband transitions using In0.53Ga0.47As/InP superlattice
    W. G. Hu, Y. Harada, A. Hasegawa, T. Inoue, O. Kojima, and T. Kita
    Progress in Photovoltaics: Research and Applications 21, pp. 472–480 (2013).

  39. High-resolution optical coherence tomography using broadband light source with strain-controlled InAs/GaAs quantum dots
    I. Tsubaki, Y. Harada, and T. Kita
    Physica Status Solidi C 9, pp. 2473–2476 (2012).

  40. Carrier dynamics of the intermediate state in InAs/GaAs quantum dots coupled in a photonic cavity under two-photon excitation
    T. Kita, T. Maeda, and Y. Harada
    Physical Review B 86, pp. 035301-1–7 (2012). Kobe University Repository Kernel

  41. Near-field photoluminescence spectroscopy of CdTe/Cd0.75Mn0.25Te tilted superlattices
    Y. Harada, T. Kita, K. Matsuda, Y. Kanemitsu, and H. Mariette
    Physica Status Solidi C 9, pp. 262–265 (2012).

  42. Extremely uniform bound exciton states in nitrogen δ-doped GaAs studied by photoluminescence spectroscopy in external magnetic fields
    Y. Harada, T. Kubo, T. Inoue, O. Kojima, and T. Kita
    Journal of Applied Physics 110, pp. 083522-1–5 (2011). Kobe University Repository Kernel

  43. Experimental and atomistic theoretical study of degree of polarization from multilayer InAs/GaAs quantum dot stacks
    M. Usman, T. Inoue, Y. Harada, G. Klimeck, and T. Kita
    Physical Review B 84, pp. 115321-1–11 (2011).

  44. Multidirectional Observation of Photoluminescence Polarization Anisotropy in Closely Stacked InAs/GaAs Quantum Dots
    Y. Ikeuchi, T. Inoue, M. Asada, Y. Harada, T. Kita, E. Taguchi, and H. Yasuda
    Applied Physics Express 4, pp. 062001-1–3 (2011).

  45. Interaction between conduction-band edge and nitrogen-related localized levels in nitrogen δ-doped GaAs
    Y. Harada, O. Kojima, T. Kita, and O. Wada
    Physica Status Solidi C 8, pp. 365–367 (2011).

  46. Bound biexciton luminescence in nitrogen δ-doped GaAs
    Y. Harada, O. Kojima, T. Kita, and O. Wada
    Physica Status Solidi B 248, pp. 464–467 (2011).

  47. Statistical fluctuation of magnetization in Mn-composition modulated Cd0.75Mn0.25Te quantum wires
    Y. Harada, T. Kita, O. Wada, and H. Ando
    Journal of Applied Physics 107, pp. 043521-1–5 (2010).

  48. Anisotropic linear polarization luminescence in CdTe/CdMnTe quantum wires
    Y. Harada, T. Kita, O. Wada, H. Ando, and H. Mariette
    Journal of Luminescence 129, pp. 1448–1453 (2009).

  49. Anisotropic magneto-optical effects in CdTe/Cd0.75Mn0.25Te quantum wire structures
    Y. Harada, T. Kita, O. Wada, H. Ando, and H. Mariette
    Physical Review B 78, pp. 073304-1–4 (2008). Kobe University Repository Kernel
    (also selected in Virtual Journal of Nanoscale Science & Technology, Volume 18, Issue 9 in Optical Properties and Quantum Optics (September 1, 2008)).

  50. Fine structure splitting of isoelectronic bound excitons in nitrogen-doped GaAs
    T. Kita, Y. Harada, and O. Wada
    Physical Review B 77, pp. 193102-1–4 (2008). Kobe University Repository Kernel

  51. Anisotropic magneto-optical effects in one-dimensional diluted magnetic semiconductors
    Y. Harada, T. Kita, O. Wada, and H. Ando
    Physical Review B 74, pp. 245323-1–7 (2006). Kobe University Repository Kernel
    (also selected in Virtual Journal of Nanoscale Science & Technology, Volume 15, Issue 1 in Nanomagnetism and Spintronics (January 8, 2007)).

  52. Valence-band mixing induced by sp-d exchange interaction in CdMnTe quantum wires
    Y. Harada, T. Kita, O. Wada, L. Marsal, H. Mariette, and H. Ando
    Physica Status Solidi C 3, pp. 667–670 (2006).

  53. Anisotropic exchange interaction caused by hole-spin reorientation in (CdTe)0.5(Cd0.75Mn0.25Te)0.5 tilted superlattices grown on Cd0.74Mg0.26Te(0 0 1) vicinal surface
    T. Kita, S. Nagahara, R. Naganuma, Y. Harada, O. Wada, L. Marsal, and H. Mariette
    Journal of Crystal Growth 275, pp. e2221–e2224 (2005).

プロシーディングス/Proceedings

  1. Yb-doped yttrium aluminum perovskite for radiation-balanced laser application
    Y. Nakayama, Y. Harada, and T. Kita
    Proceedings of SPIE 11702, pp. 117020K-1–9 (2021).

  2. Enhancement of laser cooling efficiency in rare-earth-doped oxide at elevated high temperature
    Y. Nakayama, Y. Harada, and T. Kita
    Proceedings of SPIE 11298, pp. 112980B-1–10 (2020).

  3. Optimal band gap energies for two-step photon up-conversion solar cells with partial absorptivity
    Y. Harada, T. Matsuo, S. Asahi, and T. Kita
    Proceedings of the 35th European Photovoltaic Solar Energy Conference and Exhibition, pp. 126–128 (2018).

  4. Intraband carrier dynamics in InAs/GaAs quantum dots studied by two-color excitation spectroscopy
    Y. Harada, T. Maeda, and T. Kita
    Proceedings of SPIE 8620, pp. 862008-1–7 (2013).

  5. Magneto-Photoluminescence Spectroscopy of Exciton Fine Structure in Nitrogen δ-Doped GaAs
    Y. Harada, Y. Horiuchi, O. Kojima, T. Kita, and O. Wada
    AIP Conference Proceedings 1399, 30th International Conference on the Physics of Semiconductors (edited by H. Cheong), pp. 87–88 (2011).

  6. Exciton Fine Structure of Nitrogen Isoelectronic Centers in GaAs
    Y. Harada, T. Kita, and O. Wada
    Proceedings of 20th International Conference on Indium Phosphide and Related Materials, pp. 1–3 (2008).

  7. Anisotropic Magnetic-Field Evolution of Valence-Band States in One-Dimensional Diluted Magnetic Semiconductors
    Y. Harada, T. Kita, O. Wada, and H. Ando
    AIP Conference Proceedings 893, 28th International Conference on the Physics of Semiconductors (edited by W. Jantsch and F. Schaffler), pp. 1245–1246 (2007).

国際会議/International Conference


　　　under construction

国内会議/Domestic Conference


　　　under construction