We propose an electron wave analog of the electro-optic light modulator. The current modulation in the proposed structure arises from spin precession due to the spin-orbit coupling in narrow-gap semiconductors, while magnetized contacts are used to preferentially inject and detect specific spin orientations. This structure may exhibit significant current modulation despite multiple modes, elevated temperatures, or a large applied bias.

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Chemically derived topological insulator BiSe nanoflake/Si nanowire (SiNWs) heterojunctions were fabricated employing all eco-friendly cost-effective chemical route for the first time. X-ray diffraction studies confirmed proper phase formation of BiSe nanoflakes. The morphological features of the individual components and time-evolved hybrid structures were studied using field emission scanning electron microscope. High resolution transmission electron microscopic studies were performed to investigate the actual nature of junction whereas elemental distributions at junction, along with overall stoichiometry of the samples were analyzed using energy dispersive X-ray studies. Temperature dependent current-voltage characteristics and variation of barrier height and ideality factor was studied between 50 and 300 K. An increase in barrier height and decrease in the ideality factor were observed with increasing temperature for the sample. The rectification ratio (I/I) for SiNWs substrate over pristine Si substrate under dark and near-infrared (NIR) irradiation of 890 nm was found to be 3.63 and 10.44, respectively. Furthermore, opto-electrical characterizations were performed for different light power intensities and highest photo responsivity and detectivity were determined to be 934.1 A/W and 2.30 × 10 Jones, respectively. Those values are appreciably higher than previous reports for topological insulator based devices. Thus, this work establishes a hybrid system based on topological insulator BiSe nanoflake and Si nanowire as the newest efficient candidate for advanced optoelectronic materials.

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We demonstrate an easy and scalable room-temperature synthesis of CuO nanoparticle incorporated graphitic carbon nitride composites without the aid of any inert atmosphere. First principles calculations based upon density functional theory, in addition to the experimental validations, have been employed to investigate the electronic and optical properties of the nanocomposites. An insight into the band structure tunability, phase stabilisation and the dependancy of the catalytic properties of the nanocomposites upon the amount of Cu loading, in the form of Cu oxides, have been provided in this work.