1. Improve efficiency and long lifetime UVC LEDs with wavelengths between 230 and 237 nm
- Author
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J. R. Grandusky, Akira Yoshikawa, Kazuhiro Nagase, Leo J. Schowalter, Hasegawa Ryosuke, Miller Amy C Wilson, Satoshi Yamada, Jonathan Mann, and Tomohiro Morishita
- Subjects
010302 applied physics ,Materials science ,business.industry ,General Engineering ,General Physics and Astronomy ,02 engineering and technology ,Electroluminescence ,021001 nanoscience & nanotechnology ,01 natural sciences ,law.invention ,Wavelength ,law ,0103 physical sciences ,Optoelectronics ,0210 nano-technology ,business ,Voltage ,Light-emitting diode - Abstract
We demonstrate high output power UVC-LEDs from 230 to 237 nm on AlN single-crystal substrates. The UVC-LEDs show a single peak in the electroluminescence spectrum, from 20 to 300 mA. Forward voltages were typically ~7 V at 100 mA while measured initial output powers at 237 nm, 235 nm, 233 nm and 230 nm were 2.2 mW, 1.9 mW, 1.5 mW and 1.2 mW, respectively. At 20 mA, the measured wall-plug efficiencies were 0.37%, 0.32%, 0.25% and 0.19% at the same wavelengths, respectively. These devices have demonstrated over 3600 h of lifetime operating at 20 mA.
- Published
- 2020