Light/electric modulated approach for logic functions and artificial synapse behaviors by flexible IGZO TFTs with low power consumption

Abstract

In recent years, low power electronic devices have attracted increasing interest. Here, flexible thin-film transistors (TFTs) with In–Ga–Zn–O (IGZO) as the semiconductor channel material were fabricated on polyethylene terephthalate substrates. The device exhibits good electrical properties at low operating voltage, including a high on/off ratio of ∼7.8 × 106 and high electron mobility of ∼23.1 cm2 V−1 s−1. The device also has an excellent response to visible light. With the increase of visible light intensity, the threshold voltage of IGZO TFTs decreases continuously, but the electron mobility increases gradually. Based on the unique ability of the device to respond to light, we proposed and demonstrated that a single TFT can realize different logic operations under the light/electricity mixed modulation, including ‘AND’ and ‘OR’. In addition, we also simulated some basic artificial synaptic behaviors, including excitatory postsynaptic current and paired-pulse facilitation. Thus, IGZO TFTs operating at low voltages not only have the potential to construct multifunctional optoelectronic devices, but also provide a new idea for simplifying the design of programmable logic circuits.