One-dimensional Microstructure Tungsten Gratings for Thermo Photovoltaic Applications

Samah G Babiker,Shuai Yong,Mohamed Osman Sid-Ahmed,Xie Ming

doi:10.19026/rjaset.7.526

Abstract

In this study, a one-dimensional microstructure tungsten grating is optimized for potential application as Thermo Photovoltaic (TPV) emitter. The influence of gratings geometric parameters on the spectral emittance are studied by using the Rigorous Coupled-Wave Analysis (RCWA). The results show that the spectral emittance is affected by the gratings geometrical parameters and insensitive to the direction. The optimum parameters of the proposed structure are grating period 1.4 µm, a filling ratio 0.8 and grating height 0.2 µm. A broad peak of high emittance is obtained at wavelengths between 0.5 and 1.8 μm. A peak emittance close to unity at wavelengths between 0.5 and 2 µm is achieved and it drops below 0.2 at wavelengths above 2 µm. This can be explained by the surface plasmon polaritons excitation coupled with the grating microstructures. At longer wavelengths, the emittance remains low and this is highly desired for thermo photovoltaic applications to reduce the thermal leakage due to low-energy photons that do not produce any photocurrent. The proposed structure can be used as a selective emitter for TPV applications.

Highlights

Thermo Photovoltaic (TPV) devices are capable of converting thermal infrared radiation directly into electricity by using photovoltaic effect
Effect of gratings period on the spectral emittance: The normal emittance spectra of the proposed structure when h = 0.2 μm, f = 0.8 and different grating periods (Λ) (0.5, 1, 1.4 and 2.8) μm are shown in Fig. 2a for Effect of gratings width on the spectral emittance: The effect of grating width (w) on the spectral emittance is studied with different filling ratio (ƒ) (0.5, 0.6, 0.7 and 0.8), h = 0.2 μm and grating period of Λ = 1.4 μm for Transverse Magnetic (TM) and Transverse Electric (TE) respectively at normal incidence
Effect of gratings height on the spectral emittance: Figure 4 shows the spectral emittance of the proposed structure with Λ = 1.4 μm, f = 0.8 for different grating heights (h) (0.2, 0.3 and 0.4) μm for TM waves at normal incidence

Summary

Introduction

Thermo Photovoltaic (TPV) devices are capable of converting thermal infrared radiation directly into electricity by using photovoltaic effect. They have been considered as energy conversion systems, which allow recycling of the waste heat as well as increasing the conversion efficiency (Basu et al, 2007; Wang and Zhang, 2012; Mostafa et al, 2012). The output power can be increased by using micro/nanostructures in components of TPV device (emitter and filter). This reduces the amount of unusable radiation. The development of selective emitters is very important for energy conversion and photonic devices, such as Thermo Photovoltaic (TPV) devices (Sai et al, 2005a; Nagpal et al, 2008), solar cells (Boueke et al, 2001; Zhang, 2000) and photo detectors (Sharma et al, 2002)

Methods

Results

Conclusion