Photo-induced negative differential resistance and carrier-transport mechanisms in Bi2FeCrO6 resistive switching memory devices

The new effects induced by light in the materials have important potential applications in optoelectronic multifunctional electronic devices. In this work, the double perovskite oxide Bi2FeCrO6 (BFCO) thin films were prepared by sol-gel method, and the structural, optical and electrical transport properties were investigated in detail. The good and stable resistive switching (RS) behavior with a large ROFF/RON ratio (> 60) at the small voltage of 0.5 V can be realized. Interestingly, the optical modulation conversion of the RS behavior, and the negative differential resistance (NDR) effect induced by light were found in the Au/BFCO/FTO devices. Furthermore, the mechanisms of the RS behavior, NDR effect and carrier dynamics induced by light for Au/BFCO/FTO devices were discussed, the formation the oxygen vacancies were proposed to explain the good and stable RS performance, and the effective separation of photogenerated carriers can result in the NDR effect, which is further confirmed by transient absorption spectroscopy. The conversion between RS memory and NDR effect has potential applications in optical modulation multifunctional electronic devices, electronic information and optical quantum computers.