Showing papers by "Rajib Chakraborty published in 2021"

Role of interface layer in improving the efficiency of thin film silicon solar cell

Abstract: Lower photonic conversion efficiency along with complexity of fabrication are the primary constrains for cost effective thin film solar cell production. In this work, a planar single junction structure of thin film solar cell made with two different active materials is studied, which can take care of the mentioned problems. The active materials were selected based on different parameters like band gap energy, contact potential, lattice mismatch and cost effectiveness. Simulation shows that optical absorption along with photonic conversion efficiency varies due to change in position, thickness and doping concentration of active material and so these parameters are optimized accordingly. Here an interface layer of Gallium Arsenide (GaAs) is added to the thin film Silicon (Si) layer. Our optimized Si-GaAs based thin film solar cell yields a short circuit current density of 27.51 mA/cm2 with conversion efficiency of 13.71% having a fill factor of 0.81 under AM1.5G for a typical thin film solar cell of total thickness 2 µm out of which 80% is crystalline Silicon (1.6 µm thick) and 20% is Gallium arsenide (0.4 µm thick). Thus, a simple structure with improved conversion efficiency is proposed.

Reduction of Degradation of Solar Cells Using One Dimensional Photonic Crystal Based UV Filters

Abstract: Efficiency degradation of solar cell over time is most common incident occurs in practice. Active material loses its stable carrier generation rate results in degradation in conversion efficiency after a long interaction with UV in both inorganic as well as organic solar cells. In this paper, we proposed an UV filter based on one dimensional periodic thin film structure. The effectiveness of the designed UV filter is also analyzed for most simple planer silicon thin film solar cell structure.

Characteristics of One Dimensional Photonics Structures Having Different Types of Sequences

Abstract: We discuss the optical properties, in terms of light transmission, of 1D multilayer photonic structures in the cases of periodicity and disorder. The focus will mainly be on the study of the optical properties, from a theoretical point of view, of 1D periodic photonic crystals and 1D disordered photonic structures made with bi or mono- materials. All parameters for the analysis are chosen keeping in mind that the structures can be experimentally fabricated. The designed structures can be used as optical filters in optical communication networks.

Virtual Photonic Bandgap Structure Array Using TiO 2 Rib Waveguide for Designing Optical Filters

Abstract: In this work, we have designed a mono-material based virtual photonic bandgap structure. The effect of two different materials on a single TiO2 waveguide is made by periodic removal of TiO2 from the TiO2 rib structure. This periodic removal of TiO2 results a rib-ridge waveguide structure. Due to the dissimilarities of rib and ridge structure results two different effective refractive index of TiO2. The effective refractive index of both the rib and ridge waveguide structure has been measured by FDTD for the centrally blocked wavelength of 1550 nm by Transfer Matrix Method.

Real-Time Numerical Analysis of Photonic Bandgap Structures Using Finite Difference in Time-Domain Method

Abstract: For investigating phenomena such as wave guiding, radiation and scattering, Maxwell’s equations are required to be solved numerically. The finite difference in time-domain (FDTD) method for solving Maxwell’s equations was first proposed by Kane S. Yee. As the computational capabilities of computers are increased with time, FDTD method becomes more and more pertinent for studying a variety of electromagnetic problems. Here, in this chapter, the FDTD method is discussed briefly and then spectral analysis of photonic bandgap structure (PBGS) is carried out using of FDTD method. PBGS plays an important role in the modern optical communication system for manipulating light energy. In the last section of the chapter, it is shown how the PBGSs with predetermined materials widths are used to design narrowband optical filter at 1550 nm.

Silicon waveguide as virtual photonic bandgap structure array for realizing compact optical filters

Abstract: An engineered silicon rib waveguide on Silicon-On-Insulator platform which can act as virtual photonic bandgap structure is proposed. Selective periodic etching of materials from a rib waveguide is...