"A breakthrough in gallium nitride promises to lower the cost of LED screens and transform your smartphone into an antenna, with no limits to imagination."
"Dualtronics" enables various uses on both sides of a GaN wafer.
Researchers at Cornell University, in collaboration with the Polish Academy of Sciences, have made a significant advancement in semiconductor technology by developing an innovative double-sided chip known as the "dualtronic chip." This device integrates both photonic and electronic elements onto a single Gallium Nitride (GaN) wafer. This innovation promises to reduce device sizes, improve energy efficiency, and lower manufacturing costs.
The particular crystalline structure of the GaN wafer is essential for its dual functionality. Each side of the wafer has different properties, akin to the distinct poles of a magnet. The team utilized the metal-polar side (Ga-polar) to create light-emitting diodes (LEDs), while the nitrogen-polar side (N-polar) was used to construct high-electron-mobility transistors (HEMTs). This way, they managed to configure the HEMT on one side to power the LED on the other side, a milestone that had not been achieved before with any semiconductor material.
Under the leadership of Cornell professors Debdeep Jena and Huili Grace Xing, along with lead co-authors Len van Deurzen and Eungkyun Kim, the research has been published in the journal Nature. Len van Deurzen emphasized that, to their knowledge, no one has created active devices on both sides, not even in the case of silicon, highlighting that this achievement was possible due to the polarity-dependent properties of GaN. Unlike silicon wafers, which are cubic with nearly identical sides, this design is feasible because of the peculiarities of GaN.
According to the researchers, this dualtronic approach could have immediate applications in manufacturing microLED displays, making them more affordable and energy-efficient. By integrating photonic and electronic functions into a single chip, the number of necessary components would be reduced, leading to lower production costs and a more compact device size. This advancement could significantly transform display manufacturing, making LED displays more cost-effective and compact.
The potential of this technology extends even further. The ability to use the same wafer for different functions could allow smartphone displays to be reconfigured as antennas, facilitating wireless communications through the display itself. The polarization properties of GaN and the multifunctionality of the dualtronic chip could revolutionize not only displays but also radiofrequency devices, lasers, and future 5G/6G technologies.
Debdeep Jena drew an analogy with the iPhone, explaining that while it is a phone, it also functions as a calculator, map, and internet device, illustrating the convergence aspect of this technology. The first use of "dualtronic" in this study represents a convergence of two or three functionalities, although it truly has broader potential.
This advancement could drastically change how semiconductor devices are designed and used. By eliminating the need for separate chips for different functions, dualtronic chips promise to optimize both performance and resource utilization across a range of technologies. The researchers highlight that this development represents a significant step forward, and the possible applications are "limited only by imagination."