US team builds first room temperature hybrid perovskite FETs
Researchers from Wake Forest University and the University of Utah claim to be first to successfully make halide organic-inorganic hybrid perovskite field-effect transistors and measure their electrical characteristics at room temperature. Hybrid perovskites are crystalline semiconductor materials that hold promise for making solar cells and LEDs.
"We designed the structure of these field-effect transistors that allowed us to achieve electrostatic gating of these materials and determine directly their electrical properties," said lead author, Oana Jurchescu, an assistant professor of physics at Wake Forest. "Then we fabricated these transistors with the Utah team and we measured them here in our lab."
Until now, researchers have not been able to fabricate field-effect transistors to measure the charge transport of the materials. Necessary prerequisites for a material that forms an efficient solar cell are strong optical absorption and efficient charge carrier transport, Jurchescu said. With these first generation transistors, the Wake Forest researchers were able for the first time to directly measure and calculate the electrical properties, eliminating indirect approximations.
The team obtained balanced electron and hole-transport with mobilities of around 1cm2/Vs. The processing temperature did not exceed 105 degC, which ensures the compatibility with flexible plastic substrates where these devices can be manufactured using fast, large-area deposition methods such as inkjet printing, spray deposition, etc. This first generation devices, however suffer from short lifetimes and performance degradation during operation and/or storage, which may be improved at later time.
This work is detailed in a study published online by the two research teams in the journal MRS Communications. The journal's principal editor, Alberto Salleo from Stanford University said: "These results are extremely promising as they show that hybrid perovskites can be used for low-cost thin film electronic circuits that could potentially lead to integrated optoelectronic systems and electrically pumped lasing."
Jurchescu and graduate student Yaochuan Mei, who has worked in her lab for almost five years, said: "Really, this is just the first step. Next we will look into the spin manipulation of the injected carriers in these devices and other electrical, optical and magnetic field applications."
'Electrostatic gating of hybrid halide perovskite field-effect transistors: balanced ambipolar transport at room-temperature' by Y. Meia et al, MRS Communications (2015)
