Highly insulating phase of Bi2O2Se thin films with high electronic performance

What is it about?

Bi2O2Se is highly competitive as a candidate of next-generation high-performance semiconductors. Though dubbed as semiconductor, Bi2O2Se films exhibited high conductance, i.e., metallic behavior, due to spontaneously ionized defects which give rise to electron doping. Here, we synthesized highly insulating films in a controlled way, which exhibit semiconducting behavior with channel resistance up to 1 TΩ. The electron chemical potential lies within the band gap, in some cases, even below the charge neutrality level, signifying the trace of hole-type semiconducting. The performance of insulating devices remains high, comparable to high-quality devices previously.

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Photo by Maxence Pira on Unsplash

Photo by Maxence Pira on Unsplash

Why is it important?

Semiconducting/insulating films are of practical importance in broad applications based on low-power, high-performance electronics. Insulating BOS films are more intriguing because of the expectation of various advantages including hole-type (p-type) semiconducting, ferroelectric engineering, low dark current photodetecting, photovoltaics, etc.. but the growth of which is much more challenging. Our work offers insights into electron dynamics of Bi2O2Se, moves one step further towards p-type transistors and provides a valuable playground for engineering ferroelectricity in high-performance semiconductors.