Browsing by Author "Ji Y."
Now showing items 1-17 of 17
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Advantages of the Blue InGaN/GaN Light-Emitting Diodes with an AlGaN/GaN/AlGaN Quantum Well Structured Electron Blocking Layer
Ju, Z. G.; Liu W.; Zhang Z.-H.; Tan S.T.; Ji Y.; Kyaw, Z.; Zhang, X. L.; Lu, S. P.; Zhang, Y. P.; Zhu B.; Hasanov N.; Sun, X. W.; Demir, Hilmi Volkan (American Chemical Society, 2014-03-21)InGaN/GaN light-emitting diodes (LEDs) with p-(AlGaN/GaN/AlGaN) quantum well structured electron blocking layer (QWEBL) are designed and grown by a metal− organic chemical-vapor deposition (MOCVD) system. The proposed QWEBL ... -
Comparative study of field-dependent carrier dynamics and emission kinetics of InGaN/GaN light-emitting diodes grown on (11 2-2) semipolar versus (0001) polar planes
Ji Y.; Liu W.; Erdem, T.; Chen R.; Tan S.T.; Zhang Z.-H.; Ju, Z.; Zhang X.; Sun, H.; Sun, X. W.; Zhao Y.; DenBaars, S. P.; Nakamura, S.; Demir, Hilmi Volkan (AIP Publishing, 2014)The characteristics of electroluminescence (EL) and photoluminescence (PL) emission from GaN light-emitting diodes (LEDs) grown on (11 (2) over bar2) semipolar plane and (0001) polar plane have been comparatively investigated. ... -
Decoupling contact and mirror: an effective way to improve the reflector for flip-chip InGaN/GaN-based light-emitting diodes
Zhu B.; Liu W.; Lu S.; Zhang, Y.; Hasanov N.; Zhang X.; Ji Y.; Zhang Z.-H.; Tan S.T.; Liu, H.; Demir, Hilmi Volkan (Institute of Physics Publishing, 2016)In the conventional fabrication process of the widely-adopted Ni/Ag/Ti/Au reflector for InGaN/GaN-based flip-chip light-emitting diodes (LEDs), the contact and the mirror are entangled together with contrary processing ... -
Enhanced hole transport in InGaN/GaN multiple quantum well light-emitting diodes with a p-type doped quantum barrier
Ji Y.; Zhang, Z. -H.; Tan S.T.; Ju, Z. G.; Kyaw, Z.; Hasanov N.; Liu W.; Sun X. W.; Demir, Hilmi Volkan (Optical Society of America, 2013)We study hole transport behavior of InGaN/GaN light-emitting diodes with the dual wavelength emission method. It is found that at low injection levels, light emission is mainly from quantum wells near p-GaN, indicating ... -
Facile synthesis of luminescent AgInS2–ZnS solid solution nanorods
Yang, X.; Tang, Y.; Tan S.T.; Bosman, M.; Dong, Z.; Leck K.S.; Ji Y.; Demir, Hilmi Volkan; Sun, X. W. (Wiley-VCH Verlag, 2013-04-16)Highly luminescent semiconducting AgInS2–ZnS solid solution nanorods are successfully prepared by a facile one-pot solvothermal method. The resulting solid solution nanorods with length of 32 ± 5 nm are formed by fast ... -
Fluorophore-doped core-multishell spherical plasmonic nanocavities: resonant energy transfer towards a loss compensation
Peng, B.; Zhang, Q.; Liu, X.; Ji Y.; Demir, Hilmi Volkan; Huan, C. H. A.; Sum, T. C.; Wiong, Q. (American Chemical Society, 2012-06-12)Plasmonics exhibits the potential to break the diffraction limit and bridge the gap between electronics and photonics by routing and manipulating light at the nanoscale. However, the inherent and strong energy dissipation ... -
A hole modulator for InGaN/GaN light-emitting diodes
Zhang, Z-H.; Kyaw, Z.; Liu W.; Ji Y.; Wang, L.; Tan S.T.; Sun, X. W.; Demir, Hilmi Volkan (American Institute of Physics, 2015)The low p-type doping efficiency of the p-GaN layer has severely limited the performance of InGaN/GaN light-emitting diodes (LEDs) due to the ineffective hole injection into the InGaN/GaN multiple quantum well (MQW) active ... -
Improving hole injection efficiency by manipulating the hole transport mechanism through p-type electron blocking layer engineering
Zhang, Zi-Hui; Ju, Z.; Liu W.; Tan S.T.; Ji Y.; Kyaw, Z.; Zhang X.; Hasanov N.; Sun, X. W.; Demir, Hilmi Volkan (Optical Society of America, 2014)The p-type AlGaN electron blocking layer (EBL) is widely used in InGaN/GaN light-emitting diodes (LEDs) for electron overflow suppression. However, a typical EBL also reduces the hole injection efficiency, because holes ... -
Influence of n-type versus p-type AlGaN electron-blocking layer on InGaN/GaN multiple quantum wells light-emitting diodes
Ji Y.; Zhang Z.-H.; Kyaw, Z.; Tan S.T.; Ju, Z. G.; Zhang, X. L.; Liu W.; Sun, X. W.; Demir, Hilmi Volkan (AIP Publishing, 2013-08-01)The effect of n-AlGaN versus p-AlGaN electron-blocking layers (EBLs) on the performance of InGaN/GaN light-emitting diodes is studied in this work. Experimental results suggest that the n-type EBL leads to higher optical ... -
InGaN/GaN light-emitting diode with a polarization tunnel junction
Zhang Z.-H.; Tan S.T.; Kyaw, Z.; Ji Y.; Liu W.; Ju, Z.; Hasanov N.; Sun, X. W.; Demir, Hilmi Volkan (American Institute of Physics, 2013)We report InGaN/GaN light-emitting diodes (LED) comprising in situ integrated p(+)-GaN/InGaN/n(+)-GaN polarization tunnel junctions. Improved current spreading and carrier tunneling probability were obtained in the proposed ... -
InGaN/GaN multiple-quantum-well light-emitting diodes with a grading InN composition suppressing the Auger recombination
Zhang Z.-H.; Liu W.; Ju, Z.; Tan S.T.; Ji Y.; Kyaw, Z.; Zhang, X.; Wang, L.; Sun, X. W.; Demir, Hilmi Volkan (AIP Publishing, 2014)In conventional InGaN/GaN light-emitting diodes (LEDs), thin InGaN quantum wells are usually adopted to mitigate the quantum confined Stark effect (QCSE), caused due to strong polarization induced electric field, through ... -
On the effect of step-doped quantum barriers in InGaN/GaN light emitting diodes
Zhang Z.-H.; Tan S.T.; Ju, Z.; Liu W.; Ji Y.; Kyaw, Z.; Dikme, Y.; Sun, X. W.; Demir, Hilmi Volkan (IEEE, 2013)InGaN/GaN light-emitting diodes (LEDs) make an important class of optoelectronic devices, increasingly used in lighting and displays. Conventional InGaN/GaN LEDs of c-orientation exhibit strong internal polarization fields ... -
On the origin of the electron blocking effect by an n-type AlGaN electron blocking layer
Zhang Z.-H.; Ji Y.; Liu W.; Tan S.T.; Kyaw, Z.; Ju, Z.; Zhang X.; Hasanov N.; Lu S.; Zhang, Y.; Zhu B.; Sun, X. W.; Demir, Hilmi Volkan (AIP Publishing, 2014)In this work, the origin of electron blocking effect of n-type Al 0.25Ga0.75N electron blocking layer (EBL) for c+ InGaN/GaN light-emitting diodes has been investigated through dual-wavelength emission method. It is found ... -
On the origin of the redshift in the emission wavelength of InGaN/GaN blue light emitting diodes grown with a higher temperature interlayer
Ju, Z. G.; Tan S.T.; Zhang Z.-H.; Ji Y.; Kyaw, Z. B.; Dikme, Y.; Sun, X. W.; Demir, Hilmi Volkan (AIP Publishing, 2012-03-20)A redshift of the peak emission wavelength was observed in the blue light emitting diodes of InGaN/GaN grown with a higher temperature interlayer that was sandwiched between the low-temperature buffer layer and high-temperature ... -
Polarization self-screening in [0001] oriented InGaN/GaN light-emitting diodes for improving the electron injection efficiency
Zhang Z.-H.; Liu W.; Ju, Z.; Tan S.T.; Ji Y.; Zhang X.; Wang, L.; Kyaw, Z.; Sun, X. W.; Demir, Hilmi Volkan (AIP Publishing, 2014)InGaN/GaN light-emitting diodes (LEDs) grown along the [0001] orientation inherit very strong polarization induced electric fields. This results in a reduced effective conduction band barrier height for the p-type AlGaN ... -
Self-screening of the quantum confined Stark effect by the polarization induced bulk charges in the quantum barriers
Zhang Z.-H.; Li, W.; Ju, Z.; Tan S.T.; Ji Y.; Kyaw, Z.; Zhang X.; Wang, L.; Sun, X. W.; Demir, Hilmi Volkan (AIP Publishing, 2014)InGaN/GaN light-emitting diodes (LEDs) grown along the polar orientations significantly suffer from the quantum confined Stark effect (QCSE) caused by the strong polarization induced electric field in the quantum wells, ... -
Simultaneous enhancement of electron overflow reduction and hole injection promotion by tailoring the last quantum barrier in InGaN/GaN light-emitting diodes
Kyaw, Z.; Zhang Z.-H.; Liu W.; Tan S.T.; Ju, Z. G.; Zhang, X. L.; Ji Y.; Hasanov N.; Zhu B.; Lu S.; Zhang, Y.; Teng, J. H.; Wei, S. X.; Demir, Hilmi Volkan (AIP Publishing, 2014-04-24)A three-step graded undoped-InGaN layers embedded between the GaN last quantum barrier layer and the p-AlGaN electron blocking layer was proposed and its effect on the performance of InGaN/GaN light-emitting diodes was ...