Similarly, UVB light of 294 nm-band is used in the prevention of plant diseases 7, 8 and in the production of vitamin D 3 in the human body 8, 9. Earlier studies show the use of UVB light of 310 nm narrow-band in cancer immunotherapy 3, 4, in vulgaris treatment 4, 5 and for plant growth with enriched phytochemicals 4, 6. Both Minamata Convention and 17 SDGs, with an aim to mitigate climate change, strive to eliminate the use of mercury vapour ultraviolet (UV) lamps in order to reduce the associated issue of CO 2 emission 1, 2. This research study provides a new avenue to improve the performance of high-power p-AlGaN-based UVB LEDs and other optoelectronic devices in III–V semiconductors.Īluminium gallium nitride (AlGaN) based semiconductors are one of the most promising candidates for the fabrication of smart, eco-friendly ultraviolet‐B (UVB) and deep ultraviolet (DUV) emitters that would meet the requirements of the Minamata Convention of 2020 1 and the 17 sustainable development goals (17 SDGs) of the UN 2. The enhanced performance is attributed to the use of Al-graded p-MQB EBL coupled with softly polarised p-AlGaN HSL and the highly reflective 0.4 nm-thick Ni and 200 nm-thick Al p-electrode in the UVB LED. A remarkable improvement in the efficiency of up to 9.6% and light output power of 40 mW, even in the absence of standard package, flip-chip, and resin-like lenses, is achieved on bare-wafer under continuous-wave operation at room temperature. Based on both the numerical and experimental studies, the influence of sub-nanometre scale Ni film deposited underneath the 200 nm-thick Al-film p-electrode on the optical reflectance in UVB LED is investigated. This is accomplished by the transparent nature of Al-graded Mg-doped p-AlGaN HSL for 3D holes generation and p-MQB EBL structure for holes transport toward multi-quantum-wells via intra-band tunnelling.

Using the new UVB LED design, a significant improvement in the experimental efficiency and light output power of about 8.2% and 36 mW is noticed. The study investigates the influence of Al-graded p-type multi-quantum-barrier electron-blocking-layer (Al-grad p-MQB EBL) and Al-graded p-AlGaN hole source layer (HSL) on the generation and injection of 3D holes in the active region. One of the major drawbacks in the utilisation of AlGaN-based UVB LEDs is their low efficiency of about 6.5%. Crystal growth of eco-friendly, ultrawide bandgap aluminium gallium nitride (AlGaN) semiconductor-based ultraviolet-B (UVB) light-emitting diodes (LEDs) hold the potential to replace toxic mercury-based ultraviolet lamps.

Mercury waves 9.6