Enhanced photon absorption and carrier generation in nanowire solar cells.

Overall performance of a thin film solar cell is determined by the efficiency of converting photons to electrons through light absorption, carrier generation, and carrier collection. Recently, photon management has emerged as a powerful tool to further boost this conversion efficiency. Here we propose a novel nanograting solar cell design that achieves enhanced broadband light absorption and carrier generation in conjunction with the reduced use of active and non-earth-abundant materials.

Strong enhancement of solar cell efficiency due to quantum dots with built-in charge.

We report a 50% increase in the power conversion efficiency of InAs/GaAs quantum dot solar cells due to n-doping of the interdot space. The n-doped device was compared with GaAs reference cell, undoped, and p-doped devices. We found that the quantum dots with built-in charge (Q-BIC) enhance electron intersubband quantum dot transitions, suppress fast electron capture processes, and preclude deterioration of the open circuit voltage in the n-doped structures.

Tuning the extraordinary transmission in a metallic/dielectric CDC hole array by changing the temperature.

Tunable extraordinary transmission via changing temperature of a porous metallic layer on top of a thin layer of dielectric strontium titanate (STO) was studied. The metallic layer has a through-hole array and each hole has a circular converging-diverging channel (CDC) shape, which induces the excitation of surface plasmon polaritons (SPPs) and then results in a controllable extraordinary optical transmission in the terahertz (THz) frequency range. We used a three-dimensional (3D) finite element method to analyze the transmission characteristics of the structure.

Broadband light absorption enhancement in thin-film silicon solar cells.

Currently, the performances of thin film solar cells are limited by poor light absorption and carrier collection. In this research, large, broadband, and polarization-insensitive light absorption enhancement was realized via integrating with unique metallic nanogratings. Through simulation, three possible mechanisms were identified to be responsible for such an enormous enhancement.

Tunable and polarization-selective THz range transmission properties of metallic rectangular array with a varying hole channel shape.

This paper proposes a metallic hole array of a rectangular converging-diverging channel (RCDC) shape with extraordinary transmission. We use a three-dimensional (3D) finite element method to analyze the transmission characteristics of two-dimensional metallic hole arrays (2D-MHA) with RCDC. For a straight channel MHA, when the aperture size is reduced, the transmission peaks have a blue-shift.

Tunable transmission at 100 THz through a metallic hole array with a varying hole channel shape.

Extraordinary optical transmission spectrum for a two-dimensional metallic hole array (2D-MHA) changes with the hole channel shape. In this paper a new converging-diverging channel (CDC) shape is proposed. A three-dimensional (3D) finite element method is utilized to analyze the transmission characteristics of the 2D-MHA with CDC.

Tuning the extraordinary optical transmission through subwavelength hole array by applying a magnetic field.

The transmission of light through a thin Ag film with a periodic subwavelength hole array can be influenced by the presence of the externally applied magnetic field H. Using a three-dimensional finite element method, we show that the spectral locations of the transmission peak resonances can be shifted by varying the magnitude and direction of the H. The transmission peaks have blueshift, and the higher the magnitude of H the larger the blueshift.