Combining low-dimensional layers of dissimilar metal oxide materials to form a heterojunction structure offers a potent strategy to improve the performance and stability of thin-film transistors (TFTs). Here, we study the impact of channel layer thicknesses on the operating characteristics of In2O3/ZnO heterojunction TFTs prepared via sputtering. The conduction band offset present at the In2O3/ZnO heterointerface affects the device's operating characteristics, as is the thickness of the individual oxide layers. The latter is investigated using a variety of experimental and computational modeling techniques. An average field-effect mobility ( μFE) of >50 cm2 V−1 s−1, accompanied by a low threshold voltage and a high on/off ratio (∼108), is achieved using an optimal channel configuration. The high μFE in these TFTs is found to correlate with the presence of a quasi-two-dimensional electron gas at the In2O3/ZnO interface. This work provides important insight into the operating principles of heterojunction metal oxide TFTs, which can aid further developments.

Optical generation can be divided into photoconductive generation and optical rectification. Moreover, the generation of photoconductive is more efficient than optical rectification when standard laser oscillator systems are used. At photoconductive antenna (PCA), the efficiency and terahertz (THz) power generated are affected by different parameters (e.g. incident power of laser pump, dielectric properties and the applied DC bias voltage difference). In this research, four proposed designs of PCAs are presented and compared. Furthermore, microfabrication aspects and concerns have been considered in this study, which are rarely presented in the literature. Therefore, effects of different parameters are shown in this work such as adding adhesion layer in between electrodes and the substrate, varying of gap properties and dipole length. Output frequency, photocurrent and the total effective energy of different antenna models at different values of laser power have been studied and compared.