Research on Optically-controlled Resistive Switching Effects of CdS Nanowire Memtransistor

Since it was proposed, the memtransistor is a leading candidate with powerful capabilities in field of neural morphological networks. Memtransistor is an emerging structure combining the concepts of memristors and field-effect transistor with low-dimensional materials, then both optical excitation and electrical stimuli can be used to modulate the memristive characteristics, which make it a promising multi-terminal hybrid device for synaptic structures. In this paper, a single CdS nanowire memtransistor has been constructed by the micromechanical exfoliation and alignment lithography methods. It is found that the CdS memtransistor has a good non-volatile bipolar memristive characteristics, and the corresponding switching ratio is as high as 106 in dark. While under illumination, the behavior of CdS memtransistor is similar to that of a transistor or a memristor depending on the incident wavelengths. And the memristive switching ratio varies in the range of 10 to 105 with the increase of incident wavelength in visible light range. In addition, the optical power is also found to affect the memristive characteristics of the device. All of these can be attributed to the modulation of potential barrier by abundant surface states of nanowires and the illumination influences on the carrier concentrations in nanowires.