On November 23, 2023, at the Latief Hendraningrat Hall, 2nd Floor of Dewi Sartika Building, Universitas Negeri Jakarta, the Inaugural Lecture of a Professor from the Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Negeri Jakarta, specializing in Semiconductor Material Physics, was held. The honored professor is Prof. Dr. Iwan Sugihartono, M.Si. The event was attended by guests, family members, and physics lecturers from UNJ. Prof. Iwan, who currently serves as the Chairman of the Institute for Research and Community Service (LPPM) at Universitas Negeri Jakarta, delivered a scientific oration titled “ZnO-Based Light Emitting Diode (LED): Potential for an Environmentally Friendly Future Light Source.”
In the introduction, it was emphasized that the sun is the primary source of light for humans, and light plays a crucial role in daily life. Light-emitting diodes (LEDs) represent a significant innovation in light-source technology. In the early years of LED technology development, Japanese physicists in 1993 successfully created LED lights based on the semiconductor material gallium nitride (GaN), producing blue light emissions with strong intensity, high efficiency, and environmental friendliness. This discovery marked a historic milestone and was recognized with the Nobel Prize in Physics in 2014.
The discussion then shifted to ZnO-based LED lights. Zinc oxide (ZnO) is considered an alternative semiconductor material for LEDs due to its relatively abundant natural resources. ZnO exhibits n-type semiconductor properties, a sufficiently wide energy gap, and intriguing photoluminescent characteristics, especially in the UV range. However, converting ZnO into p-type remains a significant challenge in LED technology development.
The following section covered research and the contribution of Universitas Negeri Jakarta (UNJ) to ZnO development. UNJ has focused on developing simple, economical, and environmentally friendly ZnO synthesis techniques, involving methods such as ultrasonic spray pyrolysis (USP). The research encompasses studies on the crystal structure and optical properties of ZnO thin films, as well as investigations into the nanostructure of ZnO and the influence of doping on its morphology and optical properties. Research results indicate that heat treatment and dual Cu-Al doping can alter the nanostructure morphology of ZnO and affect its natural defect distribution.
Finally, UNJ’s contribution to the development of heterojunction n-ZnO-based LED lights was highlighted. It was demonstrated that the developed LED lights produced electroluminescent emissions under reverse bias conditions, showing potential for reverse-biased diode applications. The energy band diagram of the heterojunction n-ZnO LED lights indicated the possibility of impact ionization mechanisms through the excitation of electrons from rare earth metal ions doped onto ZnO.
Congratulations and success to Prof. Dr. Iwan Sugihartono, M.Si., on achieving the academic position of Professor. May this achievement serve as a driving force for the advancement of physics and physics education at the Faculty of Mathematics and Natural Sciences, Universitas Negeri Jakarta.