A purely theoretical mathematical study has inspired an experiment that could have serious real-world applications: a crystalline material called titanium trisulfide could perform almost as well as graphene in many areas, while lacking one key weakness. The two-part study both predicts and experimentally confirms its most remarkable property: their calculations and later tests show that the electronic “bandgap” of titanium trisulfide is about that of silicon, potentially making it a better candidate than graphene to allow truly next-generation electronics.

The work here is very preliminary, but promising. It began with a computer simulation of a particular crystalline compound of titanium and sulfur — what if it could be made in a “2D” conformation, they wondered? This material would be just a single molecule thick, much like graphene but without being chemically pure. University of Nebraska-Lincoln chemist Xiao Cheng Zeng found that the computer model predicted the crystals were incredibly conductive, and had one wonderful electronic property that graphene does not: just as in silicon, the electrons orbiting within titanium-trisulfide can be easily pushed up into the conduction band, and just as easily brought back down out of it. This means that it can be turned on and off, and in theory work as the basis for a next-generation computer processor.

Happily, this purely theoretical study was supplemented by another, practical one, which took a very early stab at actually making the material in the required 2D conformation. The approach was inspired by graphene itself: Nebraska-Lincoln’s Alexander Sinitskii created a macro-scale block of titanium trisulfide and simply stuck some adhesive tape on it. The very earliest samples of graphene were made by repeatedly sticking and unsticking clear sticky tape over a powdered sample of pure carbon, and it turns out that the same approach can create short “whiskers” of titanium trisulfide, unit by unit.

Sinitskii turned these short whiskers into titanium trisulfide transistors, and tested their performance, confirming that they had the expected properties, and abilities.

What this means is that purely scientific proofs of concept like current graphene computer chips might be made fully digital, with little associated loss in speed. Right now, graphene’s lack of a useful bandgap means that graphene computers are limited to analog computation only; titanium trisulfide’s ability to switch on and off by the same process as a silicon transistor could let it power continued increases in processing speed without requiring engineers to invent a whole new sort of logical architecture.

This ability, to be directly substituted for silicon in many electronic applications, applies more widely than just processors. Its achievable bandgap also makes silicon highly absorptive to incoming energy sources like photons, and today most solar cells are based on silicon. In theory, the success with simple transistors implies that this material could also help continue advances in solar cells.

What’s most exciting here, after graphene has saturated headline space for so long, is that there was only a few months needed to take this purely theoretical 2D substance from a computer simulation to practical, working transistors. It’s possible that some of graphene’s newer, more efficient production processes might continue to work for titanium trisulfide — and if so, there’s no telling how quickly it might reach the pure production efficiency graphene science has been developing for almost a decade.

The pure transistor density already achieved with graphene, combined with the ability to create relatively “normal” digital architecture, could allow truly advances in computer processors. And combining graphene’s power efficiency with silicon’s current ability to soak up solar radiation could have an even bigger impact. It will all come down to whether this material can indeed match or exceed the current practicalities of graphene, for a price real people could ever actually afford.