Temperature effects on output characteristics of quantum dot white light emitting diode

Abstract

In this paper, we proposed quantum dot (QD) based structure for implementation of white light emitting diode (WLED) based on InGaN/GaN. The proposed structure included three layers of InGaN QD with box shapes and GaN barriers. By using of single band effective mass method and considering strain effect, piezoelectric and spontaneous polarizations internal fields, then solving Schrödinger and Poisson equations self consistently, we obtained electron and hole eigen energies and wave functions. By evaluating dipole moment matrix elements for interband transitions, the output intensity was calculated due to the interband transition between two energy levels with highest emission probability. We adjusted QDs dimensions and material compositions so that the output light can be close to the ideal white light in chromaticity diagrams. Finally, effects of temperature variations on output spectrum and chromaticity coordinates were studied. We demonstrated that temperature variations in the range of 100 to 400 K decrease output intensity, broaden output spectral profile and cause a red shift in three main colors spectrums. This temperature variation deviates (x, y) are coordinated in the chromaticity diagram, but the output color still remains close to white.

Keywords

quantum dot (QD) / InGaN / optical intensity spectrum / white light emitting diode (WLED) / chromaticity coordinate

References

[1] Nakamura S, Mukai T, Senoh M. Candela-class high-brightness InGaN/AIGaN double-heterostructure blue-light-emitting diodes. Applied Physics Letters, 1994, 64(13): 1687-1689

[2] Nakamura S. Zn-doped InGaN growth and InGaN/A1GaN double-heterostructure blue-light-emitting diodes. Journal of Crystal Growth, 1994, 145(1-4): 911-917

[3] Vurgaftmana I,Meyer J R, Ram-Mohan L R. Band parameters for III-V compound semiconductors and their alloys. Journal of Applied Physics, 2001, 89(11): 5815-5875

[4] Wu J, Walukiewicz W, Yu K M, Ager J W, Haller E E,Lu H, Schaff W J. Small band gap bowing in In_1-xGa_xN alloys. Applied Physics Letters, 2002, 80(25): 4741-4743

[5] Piprek J. Nitride Semiconductor Devices: Principles and Simulation. NewYork: WILEY-VCH, 2007

[6] Allen S C, Steck A J. A nearly ideal phosphor-converted white light-emitting diode. Applied Physics Letters, 2008, 92(14): 143309-143311

[7] Xie R J, Hirosaki N, Kimura N, Sakuma K, Mitomo M. 2-phosphorconverted white light-emitting diodes using oxynitride/nitride phosphors. Applied Physics Letters, 2007, 90(19): 191101-191103

[8] Khoshnegar M, Sodagar M, Eftekharian A, Khorasani S. Design of a GaN white light-emitting diode through envelope function analysis. IEEE Journal of Quantum Electronics, 2010, 46(2): 228-237

[9] Anikeeva P O, Halpert J E, Bawendi M G, Bulović V. Electroluminescence from a mixed red-green-blue colloidal quantum dot monolayer. Nano Letters, 2007, 7(8): 2196-2200

[10] Schubert E F, Kim J K. Solid-state light sources getting smart. Science, 2005, 308(5726): 1274-1278

[11] Chen C H, Su Y K, Sheu J K, Chen J F, Kuo C H, Lin Y C. Nitride-based cascade near white light-emitting diodes. IEEE Photonics Technology Letters, 2002, 14(7): 908-910

[12] Ozden I, Makarona E, Nurmikko A V, Takeuchi T, Krames M. A dual-wavelength indium gallium nitride quantum well light emitting diode. Applied Physics Letters, 2001, 79(16): 2532-2534

[13] Park K, Kwon M K, Cho C Y, Lim J H, Park S J. Phosphor-free white light-emitting diode with laterally distributed multiple quantum wells. Applied Physics Letters, 2008, 92(9): 091110-091112

[14] Shei S C, Sheu J K, Tsai C M, Lai W C, Lee M L, KuoC H. Emission mechanism of mixed-color InGaN/GaN multi-quantum-well light-emitting diodes. Japanese Journal of Applied Physics, 2006, 45(4): 2463-2466

[15] Rostami A, Rasooli Saghai H, Baghban Asghari Nejad H. A proposal for enhancement of optical nonlinearity in GaN/AlGaN centered defect quantum box (CDQB) nanocrystal. Solid-State Electronics, 2008, 52(7): 1075-1108

[16] Lai C Y, Hsu T M. Polarization field effect on group III-nitride semiconductors. Dissertation for the Doctoral Degree. Taiwan, Republic of China, 2003

[17] Winkelnkemper M, Schliwa A, Bimberg D. Interrelation of structural and electronic properties in In_xGa_1-xN/GaN quantum dots using an eight-band k·p model. Physical Review B: Condensed Matter and Materials Physics, 2006, 74(15): 155322-155333

[18] Wu Y R, Lin Y Y, Huang H H, Singh J. Electronic and optical properties of InGaN quantum dot based light emitters for solid state lighting. Applied Physics (Berlin), 2009, 105: 13117-13123

[19] Ranjan V, Allan G, Priester C, Delerue C. Self-consistent calculations of the optical properties of GaN quantum dots. Physical Review B: Condensed Matter and Materials Physics, 2003, 68(11): 115305-115311

[20] Sakamoto A, Sugawara M. Theoretical calculation of lasing spectra of quantum-dot lasers: effect of homogeneous broadening of optical gain. IEEE Photonics Technology Letters, 2000, 12(2): 107-109

[21] Sugawara M. Self-Assembled InGaAs/GaAs Quantum Dots. London: Academic press, 1999

[22] Asada M, Miyamoto Y, Suematsu Y. Gain and the threshold of three-dimensional quantum-box lasers. IEEE Journal of Quantum Electronics, 1986, QE-22(9): 1915-1921

[23] Fairman H S, Brill M H, Hemmendinger H. How the CIE 1931 color-matching functions were derived from Wright-Guild data. Color Research and Application, 1998, 22(1): 11-23

[24] Han D S, Asryan L V. Output power of a double tunneling-injection quantum dot laser. Nanotechnology, 2010, 21(1): 15201-15214

[25] Schubert E F,Gessmann T, Kim J K. Light-Emitting Diodes. Cambridge: Cambridge University Press, 2003

RIGHTS & PERMISSIONS

2014 Higher Education Press and Springer-Verlag Berlin Heidelberg