226 nm AlGaN/AlN UV LEDs using p-type Si for hole injection and UV reflection
Abstract
Deep ultraviolet (UV) light-emitting diodes (LEDs) at a wavelength of 226 nm based on AlGaN/AlN multiple quantum wells using p-type Si as both the hole supplier and the reflective layer are demonstrated. In addition to the description of the hole transport mechanism that allows hole injection from p-type Si into the wide bandgap device, the details of the LED structure which take advantage of the p-type Si layer as a reflective layer to enhance light extraction efficiency (LEE) are elaborated. Fabricated LEDs were characterized both electrically and optically. Owing to the efficient hole injection and enhanced LEE using the p-type Si nanomembranes (NMs), an optical output power of 225 μW was observed at 20 mA continuous current operation (equivalent current density of 15 A/cm2) without external thermal management. The corresponding external quantum efficiency is 0.2%, higher than any UV LEDs with emission wavelength below 230 nm in the continuous current drive mode. The study demonstrates that adopting p-type Si NMs as both the hole injector and the reflective mirror can enable high-performance UV LEDs with emission wavelengths, output power levels, and efficiencies that were previously inaccessible using conventional p-i-n structures.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jul 02, 2018
- Source ID
- 10.1063/1.5038044
Entities
People
- Akhil R. K. Kalapala
- Baxter Moody
- Deyin Zhao
- Dong Liu
- Jeongpil Park
- Jiarui Gong
- John D. Albrecht
- Jung-Hun Seo
- Kwangeun Kim
- Munho Kim
- Rafael Dalmau
- Sang June Cho
- Weidong Zhou
- Zhenqiang Ma
Organizations
- Defense Advanced Research Projects Agency
- Michigan State University
- University of Texas at Arlington
- University of Wisconsin–Madison