Charge-trap memory effect in spray deposited ZnO-based electrolyte-gated transistors operating at low voltage

Charge-trap memory phenomena were demonstrated in an electrolyte-gated transistor (EGT) using a spraycoated zinc oxide (ZnO) active layer and a cellulose-based electrolyte. The EGT exhibited efficient programming and erasing characteristics at low voltages, shifting the threshold voltage and the magnitude of the oncurrent. This behavior is discussed in terms of the influence of charged trapping states at the ZnO/electrolyte interface and within the ZnO bulk. The presence of these traps leads to a shift in the mobility from 0.57 & PLUSMN; 0.16 cm2 V-1 s-1 in the initial state to 0.02 & PLUSMN; 0.01 cm2 V-1 s-1 when programmed. Retention experiments revealed improved stability of the memory state when a low positive voltage is applied to the gate, indicating that the device's characteristics are extremely sensitive to the trapping/detrapping of charges at the semiconductor/ electrolyte interface. Capacitance spectroscopy measurements using planar and metal-insulator-semiconductor configurations within the same device were used to analyze the charging dynamics of the trap states at different programming states.

Automated summary

Charge-trap memory phenomena can be observed in an electrolyte-gated transistor (EGT) with a spray-coated zinc oxide (ZnO) active layer and a cellulose-based electrolyte. The EGT exhibits efficient programming and erasing characteristics at low voltages, which can shift the threshold voltage and the oncurrent magnitude. This behavior is attributed to the charged trapping states at the ZnO/electrolyte interface and within the ZnO bulk.