Yingce Liu
Yingce Liu has a total of 10 co-authors. Here are the top co-authors by number of shared publications:
- Bin Tang
Center for Photonics and Semiconductors, School of Power and Mechanical Engineering, Wuhan University, Wuhan 430072, China
2 shared publications - Hui Wan
The Institute of Technological Sciences, Wuhan University, Wuhan 430072, China
2 shared publications - Shengjun Zhou
Center for Photonics and Semiconductors, School of Power and Mechanical Engineering, Wuhan University, Wuhan, China
2 shared publications - Chengqun Gui
The Institute of Technological Sciences, Wuhan University, Wuhan 430072, China
1 shared publication - Jia Miao
Key Laboratory of Hydraulic Machinery Transients (Wuhan University), Ministry of Education, Wuhan 430072, China
1 shared publication - Jiahao Miao
Center for Photonics and Semiconductors, School of Power and Mechanical Engineering, Wuhan University, Wuhan 430072, China
1 shared publication
Latest Publications
- Open Access
Optical Characterization of GaN-Based Vertical Blue Light-Emitting Diodes on P-Type Silicon Substrate
Fabricating GaN-based light-emitting diodes (LEDs) on a silicon (Si) substrate, which is compatible with the widely employed complementary metal–oxide–semiconductor (CMOS) circuits, is extremely important for next-generation high-performance electroluminescence devices. We conducted a systematic investigation of the optical properties of vertical LEDs, to reveal the impacts of the manufacturing process on their optical characteristics. Here, we fabricated and characterized high-efficiency GaN-based LEDs with integrated surface textures including micro-scale periodic hemispherical dimples and nano-scale random hexagonal pyramids on a 4 inch p-type Si substrate. The highly reflective Ag/TiW metallization scheme was performed to decrease downward-absorbing light. We demonstrated the influence of transferring LED epilayers from a sapphire substrate onto the Si substrate on the emission characteristics of the vertical LEDs. The removal of the sapphire substrate reduced the adverse impacts of the quantum-confined Stark effect (QCSE). The influence of integrated surface textures on the light extraction efficiency (LEE) of the vertical LEDs was studied. With the injection current of 350 mA, vertical LEDs with integrated surface textures demonstrated an excellent light output power of 468.9 mW with an emission peak wavelength of 456 nm. This work contributes to the integration of GaN-based vertical LEDs into Si-based integrated circuits.
Open AccessOptical Characterization of GaN-Based Vertical Blue Light-Emitting Diodes on P-Type Silicon Substrate
Fabricating GaN-based light-emitting diodes (LEDs) on a silicon (Si) substrate, which is compatible with the widely employed complementary metal–oxide–semiconductor (CMOS) circuits, is extremely important for next-generation high-performance electroluminescence devices. We conducted a systematic investigation of the optical properties of vertical LEDs, to reveal the impacts of the manufacturing process on their optical characteristics. Here, we fabricated and characterized high-efficiency GaN-based LEDs with integrated surface textures including micro-scale periodic hemispherical dimples and nano-scale random hexagonal pyramids on a 4 inch p-type Si substrate. The highly reflective Ag/TiW metallization scheme was performed to decrease downward-absorbing light. We demonstrated the influence of transferring LED epilayers from a sapphire substrate onto the Si substrate on the emission characteristics of the vertical LEDs. The removal of the sapphire substrate reduced the adverse impacts of the quantum-confined Stark effect (QCSE). The influence of integrated surface textures on the light extraction efficiency (LEE) of the vertical LEDs was studied. With the injection current of 350 mA, vertical LEDs with integrated surface textures demonstrated an excellent light output power of 468.9 mW with an emission peak wavelength of 456 nm. This work contributes to the integration of GaN-based vertical LEDs into Si-based integrated circuits.
- Open Access
- 28 February 2019
- Published by MDPI AG in Nanomaterials
- Vol. 9 (3) , 319
Enhanced Light Extraction of Flip-Chip Mini-LEDs with Prism-Structured Sidewall
Current solutions for improving the light extraction efficiency of flip-chip light-emitting diodes (LEDs) mainly focus on relieving the total internal reflection at sapphire/air interface, but such methods hardly affect the epilayer mode photons. We demonstrated that the prism-structured sidewall based on tetramethylammonium hydroxide (TMAH) etching is a cost-effective solution for promoting light extraction efficiency of flip-chip mini-LEDs. The anisotropic TMAH etching created hierarchical prism structure on sidewall of mini-LEDs for coupling out photons into air without deteriorating the electrical property. Prism-structured sidewall effectively improved light output power of mini-LEDs by 10.3%, owing to the scattering out of waveguided light trapped in the gallium nitride (GaN) epilayer.
- 28 February 2019
- Published by MDPI AG in Nanomaterials
- Vol. 9 (3) , 319
Open AccessEnhanced Light Extraction of Flip-Chip Mini-LEDs with Prism-Structured Sidewall
Current solutions for improving the light extraction efficiency of flip-chip light-emitting diodes (LEDs) mainly focus on relieving the total internal reflection at sapphire/air interface, but such methods hardly affect the epilayer mode photons. We demonstrated that the prism-structured sidewall based on tetramethylammonium hydroxide (TMAH) etching is a cost-effective solution for promoting light extraction efficiency of flip-chip mini-LEDs. The anisotropic TMAH etching created hierarchical prism structure on sidewall of mini-LEDs for coupling out photons into air without deteriorating the electrical property. Prism-structured sidewall effectively improved light output power of mini-LEDs by 10.3%, owing to the scattering out of waveguided light trapped in the gallium nitride (GaN) epilayer.