Zobrazeno 1 - 10
of 204
pro vyhledávání: '"Han-Youl Ryu"'
Autor:
Sangjin Min, Won-Jin Choi, Dong Hwan Kim, Keuk Kim, Jaehyeok Park, Han-Youl Ryu, Jong-In Shim, Dong-Soo Shin
Publikováno v:
AIP Advances, Vol 14, Iss 10, Pp 105201-105201-4 (2024)
Red micro-light-emitting diodes (μ-LEDs) with AlGaInP/GaInP multiple quantum wells are fabricated with an oxide perimeter region to control the current injection path. When the values of the external quantum efficiency (EQE) of the 30 μm-size μ-LE
Externí odkaz:
https://doaj.org/article/7c1f442fe70c4de3bd3b63373d5269fe
Autor:
Chibuzo Onwukaeme, Han-Youl Ryu
Publikováno v:
Nanomaterials, Vol 14, Iss 17, p 1409 (2024)
The efficiency of current GaN-based blue laser diodes (LDs) is limited by the high resistance of a thick p-AlGaN cladding layer. To reduce the operation voltage of InGaN blue LDs, we investigated optimum LD structures with an indium tin oxide (ITO) p
Externí odkaz:
https://doaj.org/article/6a0d45fb9f0c42d8b5e07e40e62b03ba
Autor:
Bohae Lee, Han-Youl Ryu
Publikováno v:
Crystals, Vol 14, Iss 3, p 241 (2024)
We investigated the effect of cross-sectional shape and size on the light-extraction efficiency (LEE) of GaN-based blue nanorod light-emitting diode (LED) structures using numerical simulations based on finite-difference time-domain methods. For accu
Externí odkaz:
https://doaj.org/article/c63dc2c3aff04a5a96d462c6d1192d7e
Publikováno v:
IEEE Photonics Journal, Vol 12, Iss 2, Pp 1-10 (2020)
We conducted a systematic investigation of the light extraction efficiency (LEE) of GaN-based vertical micro-scale light-emitting diode (μ-LED) structures using three-dimensional finite-difference time-domain (FDTD) simulations. The LEE of μ-LED st
Externí odkaz:
https://doaj.org/article/148fa5e1ce134184a514776c29052c0a
Publikováno v:
Nanomaterials, Vol 12, Iss 14, p 2405 (2022)
We investigated the temperature dependence of the electron leakage current in the AlGaN electron-blocking layer (EBL) of an InGaN/GaN blue light-emitting diode (LED) structure at temperatures between 20 and 100 °C. The percentage of electron leakage
Externí odkaz:
https://doaj.org/article/cf39a04909a64fa7949fb740bae66f72
Autor:
Chibuzo Onwukaeme, Han-Youl Ryu
Publikováno v:
Crystals, Vol 11, Iss 11, p 1335 (2021)
In GaN-based laser diode (LD) structures, Mg doping in p-type-doped layers has a significant influence on the device performance. As the doping concentration increases, the operation voltage decreases, whereas the output power decreases as a result o
Externí odkaz:
https://doaj.org/article/4f52d2a0aed44737ae0565671979392e
Publikováno v:
Micromachines, Vol 12, Iss 8, p 999 (2021)
We investigated the crystallinities of poly silicon (poly Si) annealed via green laser annealing (GLA) with a 532-nm pulsed laser and blue laser annealing (BLA) with 450-nm continuous-wave lasers. Three-dimensional heat transfer simulations were perf
Externí odkaz:
https://doaj.org/article/dec3ebe9931e41a38c242fdb109d9871
Autor:
Han-Youl Ryu
Publikováno v:
Nanoscale Research Letters, Vol 12, Iss 1, Pp 1-7 (2017)
Abstract GaN-based blue laser diodes (LDs) may exhibit anomalous temperature characteristics such as a very high characteristic temperature (T 0) or even negative T 0. In this work, temperature-dependent characteristics of GaN-based blue LDs with InG
Externí odkaz:
https://doaj.org/article/1b248d924023427db6d8bad266755796
Publikováno v:
AIP Advances, Vol 9, Iss 1, Pp 015009-015009-5 (2019)
We experimentally investigated the temperature dependence of the color rendering index (CRI) of a phosphor-conversion (PC) white light-emitting diode (LED) composed of a GaN-based blue LED chip and yttrium aluminum garnet doped with Ce3+ (YAG) phosph
Externí odkaz:
https://doaj.org/article/6d0208746a744c3b8ee8b21fea25a2d3
Autor:
Dong Yeong Kim, Guan-Bo Lin, Sunyong Hwang, Jun Hyuk Park, David Meyaard, E. Fred Schubert, Han-Youl Ryu, Jong Kyu Kim
Publikováno v:
IEEE Photonics Journal, Vol 7, Iss 1, Pp 1-9 (2015)
A genetic algorithm is employed to find an optimum epitaxial structure of multiple quantum wells (MQWs) and electron-blocking layer (EBL) for a GaInN-based light-emitting diode (LED). The optimized LED is composed of locally Si-doped quantum barriers
Externí odkaz:
https://doaj.org/article/ee16a764c23c47e798f055838593dee4