Improving the Performance of Light Trapping in Crystalline Silicon Solar Cell through Effective Surface Texturing

Abstract

We investigate the effect of surface texturing on the light trapping properties of Silicon wafers as a function of reflection reduction and surface morphology. This was achieved by structuring a random square-based pyramids pattern on the surface of Silicon substrate using anisotropy etching. The light trapping effect was optimized for silicon solar cells by investigating the dependence of the silicon surface texturing on the process parameters such as etchant concentration, etching time and temperature. We study the surface morphology by analyzing the surface behaviour of the textured substrate using the atomic force microscope and scanning electron microscope. The results of roughness and optical reflection were obtained using the surface profiler and the UV/VIS the spectrometer respectively. In addition, an analytical modelling method was developed to determine the angles of incidence of light rays with each of the facets of the pyramids and the coordinate of the reflected light rays. The method used here is based on 3-D vector geometry of the pyramidal facets. The optimum parameters are found to be 40min, a temperature of 80oC and with KOH/IPA/DI in the ratio [2:4:46] by volume, yielding a surface roughness over 600 nm and a relative optical reflectance in the visible spectrum less than 10%, using polished Si as reference. The results and analysis of both the modelled and measured reflectance, suggest that the performance of the light trapping technique has a big potential in silicon solar cells application.

Fabrication of Oxide Passivated and Antireflective Thin Film Coated Emitter Layer in Two Steps for the Application in Photovoltaic

“…Using Veeco Dektak-150 surface profiler for the chemically textured silicon wafer, for 10 minutes etching, the average pyramid height was measured 2.937 µm which is in the range (2-3 µm) suitable for light trapping in photovoltaic devices 40) . Larger pyramid size of 10-15 µm 41) was observed for etching time of 30-50 minutes 42) .…”

Atomic force microscopy analysis of alkali textured silicon substrates for solar cell applications

“…Potassium hydroxide (KOH) and isopropyl alcohol (IPA) are the most preferred alkaline solutions used for anisotropic etching of silicon substrates [13][14][15][16][17][18][19][20][21]. Furthermore, the surface texturing of (100)-oriented silicon substrates can be used to improve the absorbance characteristics of silicon substrates [6], [21]. Given that such improved absorption can be used to increase photo-conversion efficiencies of silicon solar cells, there is a need to study the micro-pyramidal geometries of textured silicon substrates.…”

A study on the reliability and performance of solar powered street lighting systems

“…The most significant failure in outdoor/field PVs systems are: delamination [23], junction box failure [17], frame breakage [17], cell cracks [24], [25], burn marks [17], potential induced degradation [17], and defective bypass diodes [17]. While on the other, the common failures in laboratory PVs cells include: Interfacial and contact failure [26], delamination [27,28], adhesion loss [29], contact degradation [26], crack due to bending and stretching of organic solar cells [26][27], [30] and cell cracks due to surface texturing [31][32]. Nevertheless, there is a need for more data on the failure, reliability and performance of PV systems that are deployed across the different terrestrial regions around the world.…”