MoS2 nanosheet channel and guanine DNA-base charge injection layer for high performance memory transistors

Abstract

DNA polymers have been studied in the research areas of information and nanotechnology as well as biotechnology with various benefits such as natural plenitude, biodegradability and low toxicity. Here we demonstrate a charge injection type non-volatile memory field-effect transistor (FET) with one DNA-base small molecule, guanine, which is coupled with a MoS₂ nanosheet channel as a trapping or charge injection layer material. Owing to the unique properties of the guanine layer and the extremely thin MoS₂ nanosheet, our non-volatile memory MoS₂ FETs exhibit a more than 3 V memory window under a 35 V/−15 V gate voltage pulse for Program/Erase (or trapping/detrapping), maintaining a high Program/Erase ratio of ∼10³ for longer than 1000 s at least. Superior dynamic Program/Erase cycles were performed with a memory inverter composed of two memory FETs connected in series. Such non-volatile memory properties have been mostly well observed even after 45 days, since the trapped electron charges were stably stored in the guanine layer.