This report covers the fabrication of a fully transparent resistive random access memory (TRRAM) device based on an ITO (indium tin oxide)/ZnO/ITO capacitor structure and its resistive switching characteristics. The fabricated TRRAM has a transmittance of 81% (including the substrate) in the visible region and an excellent switching behavior under 3V. The retention measurement suggests that the memory property of the TRRAM device could be maintained for more than 10years. We believe that the TRRAM device presented in this work could be a milestone of future see-through electronic devices.

Toxic doping gases are usually used to produce hydrogenated amorphous silicon (a-Si:H) layers in thin-film solar cells (TFSCs). Hence, an alternative structure that avoids the use of toxic gases is desirable. In this work, we replaced both the p-type-a-Si:H and n-type-a-Si:H layers simultaneously in a normal TFSC to form a structure that is dopant-free. Molybdenum oxide (MoO3) and lithium fluoride were used as the p-type and n-type layers, respectively. The effects of the deposition method and the thickness of the MoO3 layer on the device performance were investigated. The power-conversion efficiency of the optimized hybrid solar cell reached a maximum of 7.08%, which is remarkable considering the novel structure of the dopant-free devices. The light stability of the devices with and without MoO3 was also compared: the light stability of the device with MoO3 was found to be much better than that of the device without MoO3 and with p-i-n Si layers. This was ascribed to the insignificant number of defect sites generated by the nondoping elements, which led to a less contaminated, more compact, and smoother oxide surface, resulting in an increase in the electron lifetime and improved light stability. This work opens up a new direction toward the development of a truly dopant-free device that does not involve the use of toxic gases during fabrication and provides the potential for further enhancement of the efficiency of future dopant-free solar cells.

We demonstrated that an Al/p-type amorphous silicon (p-a-Si)/Al switching device exhibits stable, nonvolatile resistive switching characteristics as well as reliable data retention at 85 °C. It is directly observed that the conducting filament is created after electroforming and incorporates the top metal migrated or diffused into a-Si layer. In addition, by analyzing the constitution of the conducting filament, we investigated the microscopic nature of the conducting filament. These results suggest that the Al/p-a-Si/Al device has potential for future nonvolatile memory applications.

Abstract-We report a new structure of high-responsivity photodetectors that utilizes the transparent and metallic zinc oxide (ZnO) gate in bulk silicon metal-oxide-semiconductor field-effecttransistor photodetectors. The device has a small optical window only in the channel region, and all other regions (depletion) are protected from external light. Whereas the amplification of photocurrent by external light was not significant at the floated or positively biased substrate, the photocurrent was enhanced at the grounded or negatively biased substrate due to the decrement of the recombination rate in the n-channel MOSFET. Responsivity was in excess of 1500 A/W under white-light illumination, which is higher than that of conventional photodetectors with the semitransparent polycrystalline-silicon gate.Index Terms-Field-effect phototransistor, photodetector, transparent gate.

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