Perovskites have made a name for themselves in solar cells, but not so much in the world of integrated circuits. In a traditional metal oxide transistor setup, the material simply won’t allow current modulation for more than a few cycles. As it turns out, that can be remedied by using a more modern gate oxide. By exchanging silicon dioxide for hafnium oxide, researchers of Rice University succeeded in creating a perovskite MOSFET that switches on and off more than 100 times without breaking down.
The instability of perovskites in a transistor channel is thought to be a result of structural defects, which absorb some of the energy from the gate electrode. Increasing the voltage helps, but silicon dioxide insulators can only handle so much. Hafnium oxide, which has been used in advanced ICs for a decade or so, provides more protection. That’s why the US researchers managed to make a more durable perovskite transistor with it.
Performance-wise, the transistor doesn’t exactly impress, though. The mobility of charge carriers is quite low and the on/off ratio needs to be improved by a factor of 100 at least. But, interestingly, the transistor can function as both n-type and p-type. As this could make circuit design easier, it’s probably worth exploring perovskite transistors a bit more.