As the size of transistors begin to approach theoretical minimums and Moore’s law starts to fade away, improving how well semiconductors perform is paramount to increasing the power of our electronics. Now a team of researchers led by Rutgers University has discovered a new method to increase semiconductor performance in a most novel way.
As a refresher, a semiconductor is a material that conducts electricity whos conductivity can be adjusted based on external stimuli such as temperature. Semiconductors come in two forms, organic, and inorganic, and are the foundation of modern electronics. Inorganic semiconductors are built using materials such as silicon, while organic semiconductors are made of organic molecules (mainly consisting of carbon and hydrogen atoms) that form light, flexible crystals called van der Waals molecular crystals.
Organic transistors based on single crystals of rubrene, a hydrocarbon, can roughly double the speed of electricity flowing through them when a crystal is slightly bent (strained). This useful behavior cannot be easily achieved with traditional semiconductors made, for example, of silicon. Molecules of rubrene are arranged in a herringbone pattern (upper left), forming highly ordered semiconducting molecular crystals that can be used to create rigid (upper right) or flexible (lower left) high-performance organic transistors, based on thick or ultra-thin single crystals, respectively. An example of a freestanding rubrene transistor is shown on a fingertip (lower right).
Image: Vitaly Podzorov/Rutgers University-New Brunswick
Organic semiconductors are widely used in the creation of optoelectronics, environmental sensors, and have proven to be quite favorable to flexible and printed electronics such as solar cells. More importantly, organic semiconductors are cheaper to produce than silicon or germanium-based semiconductors, making them more favorable from a manufacturing standpoint. Additionally, since organic semiconductors are more friendly to flexing, they can be used in applications where rigid semiconductors might suffer failure due to flexing.
Regardless of being organic or inorganic, a key property to high-quality semiconductors is how fast they can flow electricity. This is another advantage that is starting to appear in organic semiconductors, and this new research from Rutgers is helping to widen that gap. The study posted in the journal of Advanced Sciences shows that by bending organic semiconductors slightly, the strain that is caused in the crystalline structure actually allows electrons to flow faster through the material.
The study shows that just a 1-percent bend in an organic semiconductor-based transistor can almost double the speed at which electrons flow through it. Don’t go bending your Raspberry Pi just yet though, as more research needs to be done, and your Pi is made from inorganic semiconductors anyway.
“One of the most important characteristics of organic and inorganic semiconductors is how fast electricity can flow through electronic devices. Thanks to progress over the last decade, organic semiconductors can perform roughly 10 times better than traditional amorphous silicon transistors. Tuning semiconductors by bending them is called “strain engineering,” which would open a new avenue of development in the semiconductor industry if implemented successfully. But until now, there were no conclusive experimental results on how bending organic semiconductors, including those in transistors, may affect the speed of electricity flowing in them,” the team said in a press release.
While I can not pretend to fully grasp the implications of this research, I can see the benefits of improving how fast our electronics perform, especially with the so-called “atomic wall” drawing closer every year. At some point in the very near future, we will not be able to make transistors any smaller, and without a revolutionary discovery in quantum computing being made, the only way we will have to speed up our electronic devices will be to increase die size, or improve how fast electricity flows through those same chips. As someone who has written extensively about Moore’s Law and PC performance, this new discovery excites me and leaves me hopeful that one day a bent CPU might not equal a disaster.
Source: Rutgers.edu