Abstract
The hole injection is one of the bottlenecks that strongly hinder the quantum efficiency and the optical power for deep ultraviolet light-emitting diodes (DUV LEDs) with the emission wavelength smaller than 360 nm. The hole injection efficiency for DUV LEDs is co-affected by the p-type ohmic contact, the p-type hole injection layer, the p-type electron blocking layer and the multiple quantum wells. In this report, we review a large diversity of advances that are currently adopted to increase the hole injection efficiency for DUV LEDs. Moreover, by disclosing the underlying device physics, the design strategies that we can follow have also been suggested to improve the hole injection for DUV LEDs.
Highlights
Compared to florescence-based deep ultraviolet emitters, III-nitride based deep ultraviolet light-emitting diodes (DUV LEDs) have shown a diversity of excellences including no mercury, low-voltage consumption, DC driving, small size and portability, and they can be widely used in water sterilization, air purification, medical therapy, biological analysis et al [1,2]
To acquire the intraband-tunneling-assisted hole possesses the bulk p-electron blocking layer (EBL), the major transport for holes is via the thermionic emission, which is strongly injection, we have recently proposed a p-EBL with a very thin insertion layer that has a smaller energy affectedband by the offset and thethe hole concentration, i.e., Φare
A larger valence the point proposed by Tsai et al, since we find that the hole concentration in quantum well closest band
Summary
Compared to florescence-based deep ultraviolet emitters, III-nitride based deep ultraviolet light-emitting diodes (DUV LEDs) have shown a diversity of excellences including no mercury, low-voltage consumption, DC driving, small size and portability, and they can be widely used in water sterilization, air purification, medical therapy, biological analysis et al [1,2]. As Piprek has summarized, the Auger recombination coefficient scales down as the energy band gap becomes large, e.g., in the case of Al-rich AlGaN quantum wells [16] It is not clear if the Auger recombination plays an important role in influencing the IQE for DUV LEDs at the current stage [17]. To guarantee a smooth hole injection, one shall (1) increase the hole tunneling efficiency from the p-type ohmic contact into the hole supplier; (2) improve the hole transport within the hole supplier; (3) reduce the hole blocking effect that is caused by the p-EBL; (4) increase the hole concentration in the MQWs. In this work, we will conduct in-depth review on the various proposed approaches to increase the hole injection capability for DUV LEDs. 2. Increase the Hole Injection Efficiency from the p-Type Ohmic Contact into the Hole Supplier firstInjection obstacle that the injected holesthe have to overcome arises from the p-GaN/p-ohmic
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
