Browsing by Author "Zheng, K."

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    Improved InGaN/GaN light-emitting diodes with a p-GaN/n-GaN/p-GaN/n-GaN/p-GaN current-spreading layer
    (Optical Society of American (OSA), 2013) Zhang, Z.-H.; Tan, S.T.; Liu W.; Ju, Z.; Zheng, K.; Kyaw, Z.; Ji, Y.; Hasanov, N.; Sun X.W.; Demir, Hilmi Volkan
    This work reports both experimental and theoretical studies on the InGaN/GaN light-emitting diodes (LEDs) with optical output power and external quantum efficiency (EQE) levels substantially enhanced by incorporating p-GaN/n-GaN/p-GaN/n-GaN/p-GaN (PNPNP-GaN) current spreading layers in p-GaN. Each thin n-GaN layer sandwiched in the PNPNP-GaN structure is completely depleted due to the built-in electric field in the PNPNP-GaN junctions, and the ionized donors in these n-GaN layers serve as the hole spreaders. As a result, the electrical performance of the proposed device is improved and the optical output power and EQE are enhanced. © 2013 Optical Society of America.
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    An indium-free transparent resistive switching random access memory
    (IEEE, 2011-02-28) Zheng, K.; Sun, X. W.; Zhao, J. L.; Wang, Y.; Yu, H. Y.; Demir, Hilmi Volkan; Teo, K. L.
    We report an indium-free transparent resistive switching random access memory device based on GZO-Ga(2)O(3)-ZnO-Ga(2)O(3)-GZO structure by metal-organic chemical vapor deposition. The memory device shows good transmittance in the visible region and bipolar resistive switching behavior with good cycling characteristics and retention time under room temperature. The conduction and resistive switching mechanism was discussed based on filament theory.