Aluminum Nitride Nanowire Light Emitting Diodes: Breaking the Fundamental Bottleneck of Deep Ultraviolet Light Sources
Journal Article - Open Access
McGill University Montreal, Quebec Canada
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Despite broad interest in aluminum gallium nitride AlGaN optoelectronic devices for deep ultravioletDUV applications, the performance of conventional AlGaN planar devices drastically decays when approaching the AlN end, including low internal quantum efficiencies IQEs and high device operation voltages. Here we show that these challenges can be addressed by utilizing nitrogen N polar AlGaN nanowires grown directly on Si substrate. By carefully tuning the synthesis conditions, a record IQE of 80can be realized with N-polar AlN nanowires, which is nearly ten times higher compared to high quality planar AlN. The first 210 nm emitting AlN nanowire light emitting diodes LEDs were achieved, with a turn on voltage of about 6 V, which is significantly lower than the commonly observed 20 40 V. This can be ascribed to both efficient Mg doping by controlling the nanowire growth rate and N-polarity induced internal electrical field that favors hole injection. In the end, high performance N-polar AlGaN nanowire LEDs with emission wavelengths covering the UV-BC bands were also demonstrated.
- Electrooptical and Optoelectronic Devices