Open AccessMonolithic stacked blue light-emitting diodes with polarization-enhanced tunnel junctions
Author(s) -
YenKuang Kuo,
Ya Hsuan Shih,
Jih Yuan Chang,
Wei Chih Lai,
Heng Liu,
Fang Ming Chen,
Ming Lun Lee,
Jinn-Kong Sheu
Publication year - 2017
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.25.00a777
Subject(s) - light emitting diode , materials science , optoelectronics , tunnel junction , quantum tunnelling , diode , voltage , junction temperature , optics , polarization (electrochemistry) , power (physics) , electrical engineering , physics , quantum mechanics , engineering , chemistry
Monolithic stacked InGaN light-emitting diode (LED) connected by a polarization-enhanced GaN/AlN-based tunnel junction is demonstrated experimentally in this study. The typical stacked LEDs exhibit 80% enhancement in output power compared with conventional single LEDs because of the repeated use of electrons and holes for photon generation. The typical operation voltage of stacked LEDs is higher than twice the operation voltage of single LEDs. This high operation voltage can be attributed to the non-optimal tunneling junction in stacked LEDs. In addition to the analyses of experimental results, theoretical analysis of different schemes of tunnel junctions, including diagrams of energy bands, diagrams of electric fields, and current-voltage relation curves, are investigated using numerical simulation. The results shown in this paper demonstrate the feasibility in developing cost-effective and highly efficient tunnel-junction LEDs.