A groundbreaking paper on hybrid perovskites, one of the hottest solar cell and LED materials, just published in MRS Communications, a flagship journal of the Materials Research Society.
First created in 2012, perovskite solar cells have shown great promise in recent years as an affordable alternative to other solar technologies, such as photovoltaic cells typically used in solar panels. Now scientists from Wake Forest University and the University of Utah have described the very first example of field-effect modulation in perovskites (i.e. their use in transistors), with potentially far-reaching implications.
Until now, researchers have been unable 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.
With these first generation transistors, researchers from Wake Forest and Utah were able for the first time to directly measure the ability of hybrid perovskites to transport charge, widening the spectrum of possible applications of these materials.
MRS Communications Principal Editor, Alberto Salleo from Stanford University, explains: “Hybrid inorganic-organic halide perovskites are a new promising materials family for low-cost and even solution-processable thin film optoelectronics. Efficient solar cells and bright light-emitting diodes using hybrid perovskites have already been demonstrated, taking the thin film electronics community by storm.
“In spite of estimates of high mobilities and low defect densities, field-effect devices have so far not been demonstrated. Indeed, electrostatic gating, the key operating mechanism of transistors, has remained elusive. A large part of the perovskite community remains convinced that field-effect modulation is impossible in these materials, highlighting how little is known about surfaces and defects in these materials.”
“This article is the first report of the fabrication and room-temperature operation of field-effect transistors based on hybrid perovskites. In perovskite transistors, transport is ambipolar with balanced electron and hole mobilities. 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.”
This timely paper is of enormous interest to a broad range of scientists, given the recent surge in research on perovskite based solar cells. The high efficiencies and low production costs of the crystalline material have already made it the fastest advancing solar technology to date and a commercially attractive option, with start-up companies promising modules on the market by 2017.