Comparative analysis of room temperature plasmonic graphene hot electron bolometric photodetectors

We appraise a waveguide-integrated plasmonic graphene photodetector based on the hot carrier photo-bolometric effect, with performance characterized simultaneously by high responsivity, on the scale of hundreds of A/W, and high speed on the scale of 100’s of GHz. Performance evaluation is based on a theory of bolometric effect originating from the band nonparabolicity of graphene. Results compare favorably with the state-of-the-art plasmonic bolometric photodetectors, predicting up to two orders of magnitude increase in a responsivity while keeping speed on the same level, defined by the electron-lattice scattering time in graphene.

Wave packet broadening through different semiconducting mediums: A meshless multi-quadric radial base function study

In this paper, we have studied the effect of conduction band nonparabolicity on wave packet broadening in different semiconducting mediums. Here, through a fourth derivative of the wavefunction, we have included the nonparabolicity effect into the one-dimensional Schrödinger equation. We have solved this equation by means of a meshless radial base function approach. We have compared five different semiconducting mediums GaAs, GaN, AlN, InSb and GaSb and showed that the wave packet broadens slower in systems with larger effective masses and smaller nonparabolicity parameters. Thus, we can manage and control the dispersion of a Gaussian wave packet utilizing the nonparabolicity and effective mass parameters.

Conduction-band nonparabolicity effect on refractive index and phase match in asymmetric quantum wells pumped by two infrared beams

An asymmetric quantum well (AQW) system that is pumped by two infrared beams is designed to generate terahertz (THz) waves. The refractive index and phase mismatch associated with the intersubband transition of the AQW structure are calculated and analyzed for both present and absent conduction band nonparabolicity. The calculated results reveal that, for increasing wavelengths, the refractive index of the AQW for the short-wavelength pump beam varies more than 0.83 and undergoes a 0.204 [Formula: see text]m redshift, when the conduction band nonparabolicity is considered. The variation of the refractive index of the AQW with the long-wavelength pump beam, changes from 0.225 to 0.316 after considering the conduction-band nonparabolicity. In addition, no redshift is observed. Whether the refractive index of one pump beam with its specific wavelength increases is determined mainly by the linear terms. However, for increasing the other pump wavelengths, the refractive index of one pump beam mainly depends on the nonlinear terms. Subband energy-levels and dipole transition matrix elements show noticeable changes due to conduction-band nonparabolicity, which change the refractive index. Phase matching can be achieved by adjusting the wavelength of the two pump beams. However, both phase mismatch and coverage increase when the conduction band nonparabolicity is considered.

Effect of electric field, dielectric screening and conduction band nonparabolicity of donor in a quantum dot

The effect of electric field, dielectric screening, conduction band nonparabolicity and effective mass mismatch of a hydrogenic donor in a GaAs/Ga[Formula: see text]Al[Formula: see text]As spherical quantum dot is investigated by assuming parabolic confinement using variational method. In the present work we obtain the increase of binding energy by decreasing the dot size for certain dot radii (50 Å) and the screening function gives uniformly larger values for smaller dot size. The effect of electric field and temperature decrease the donor binding energy whereas the conduction band nonparabolicity leads to increased binding energy.