Photovoltaic Device Applications of Porous Silicon

1992 ◽  
Vol 283 ◽  
Author(s):  
Y. S. Tsuo ◽  
M. J. Heben ◽  
X. Wu ◽  
Y. Xiao ◽  
C. A. Moore ◽  
...  
Keyword(s):  
Solar Cell ◽  
Crystalline Silicon ◽  
Light Trapping ◽  
Cell Structure ◽  
Surface Texturing ◽  
Point Contact ◽  
Front Surface ◽  
Back Surface ◽  
Porous Si ◽  
Device Applications

ABSTRACTWe report on the results of our investigation of using porous Si to enhance the performance of crystalline silicon photovoltaic solar cells. Possible approaches include using the porous Si for (1) surface texturing to enhance light trapping, (2) front or back surface fields because of its wider bandgap, and (3) photon color conversion of blue light to longer wavelengths that have higher quantum efficiency in a Si solar cell. In our surface texturing study, a porous-Si-covered single-crystal Si wafer showed an integrated reflectance of only 1.4% at 500-nm wavelength compared to about 40% for a polished Si surface. For our solar cell study, we used a point-contact cell structure with diffused p+ and n+ point contacts on the back of the cell. This cell structure allows us to form the porous Si on the front surface after both the junction formation and the evaporation and alloying of metal contacts.

COMBINED EFFECT OF MECHANICAL GROOVING AND STAIN-ETCHED SURFACE ON OPTICAL AND ELECTRICAL PROPERTIES OF CRYSTALLINE SILICON SUBSTRATES

2014 ◽  
Vol 21 (03) ◽  
pp. 1450041 ◽  
Author(s):  
AHMED ZARROUG ◽  
LOTFI DERBALI ◽  
RACHID OUERTANI ◽  
WISSEM DIMASSI ◽  
HATEM EZZAOUIA
Keyword(s):  
Crystalline Silicon ◽  
Light Trapping ◽  
Front Surface ◽  
Minority Carrier Lifetime ◽  
Combined Effect ◽  
Machining Process ◽  
Silicon Substrates ◽  
Textured Surface ◽  
Crystalline Silicon Solar Cell ◽  
Simple Method

This paper investigates the combined effect of mechanical grooving and porous silicon (PS) on the front surface reflectance and the electronic properties of crystalline silicon substrates. Mechanical surface texturization leads to reduce the cell reflectance, enhance the light trapping and augment the carrier collection probability. PS was introduced as an efficient antireflective coating (ARC) onto the front surface of crystalline silicon solar cell. Micro-periodic V-shaped grooves were made by means of a micro-groove machining process prior to junction formation. Subsequently, wafers were subjected to an isotropic potassium hydroxide ( KOH ) etching so that the V-shape would be turned to a U-shape. We found that the successive treatment of silicon surfaces with stain-etching, grooving then alkaline etching enhances the absorption of the textured surface, and decreases the reflectance from 35% to 7% in the 300–1200 nm wavelength range. We obtained a significant increase in the overall light path that generates the building up of the light trapping inside the substrate. We found an improvement in the illuminated I–V characteristics and an increase in the minority carrier lifetime τeff. Such a simple method was adopted to effectively reinforce the overall device performance of crystalline silicon-based solar cells.

Efficiency Enhancement of Photovoltaic/Thermal Module Using Front Surface Cooling Technique in Winter and Summer Seasons: An Experimental Investigation

2019 ◽  
Vol 141 (9) ◽  
Author(s):  
Himanshu Sainthiya ◽  
Narendra S. Beniwal
Keyword(s):  
Solar Cell ◽  
Surface Water ◽  
Surface Temperature ◽  
Front Surface ◽  
Climatic Conditions ◽  
Back Surface ◽  
Water Cooling ◽  
Performance Parameters ◽  
Surface Cooling ◽  
Overall Efficiency

This paper presents the effect of the front surface water cooling on performance parameters (solar cell temperature, back surface temperature, outlet water temperature, electrical efficiency, overall efficiency, etc.) of photovoltaic/thermal (PV/T) module in both winter and summer seasons in Indian climatic conditions. A mathematical model of PV/T module considering energy balance equations has also been presented. A comparative analysis of performance parameters obtained analytically and experimentally has also been presented. A fair agreement has also been found between analytical and experimental results which is supported by correlation coefficient of approximately unity and root mean square error of 10–14%. By front surface water cooling, solar cell and back surface temperature of PV/T module have been found to decrease considerably which in turn resulted in enhanced electrical and overall efficiency of module in winter and summer seasons.

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

2015 ◽  
Vol 1132 ◽  
pp. 144-159 ◽  
Author(s):  
A.A. Fashina ◽  
K.K. Adama ◽  
M.G. Zebaze Kana ◽  
Winston O. Soboyejo
Keyword(s):  
Solar Cells ◽  
Surface Morphology ◽  
Crystalline Silicon ◽  
Light Trapping ◽  
Surface Texturing ◽  
Visible Spectrum ◽  
Silicon Solar Cells ◽  
Etching Time ◽  
Crystalline Silicon Solar Cell ◽  
Light Rays

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.

scholarly journals PECVD-ONO: A New Deposited Firing Stable Rear Surface Passivation Layer System for Crystalline Silicon Solar Cells

2008 ◽  
Vol 2008 ◽  
pp. 1-10 ◽  
Author(s):  
M. Hofmann ◽  
S. Kambor ◽  
C. Schmidt ◽  
D. Grambole ◽  
J. Rentsch ◽  
...  
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Crystalline Silicon ◽  
Internal Quantum Efficiency ◽  
Rear Surface ◽  
Chemical Vapour ◽  
Passivation Layer ◽  
Nuclear Reaction Analysis ◽  
Back Surface ◽  
Layer System

A novel plasma-enhanced chemical vapour deposited (PECVD) stack layer system consisting of a-SiOx:H, a-SiNx:H, and a-SiOx:H is presented for silicon solar cell rear side passivation. Surface recombination velocities below 60 cm/s (after firing) and below 30 cm/s (after forming gas anneal) were achieved. Solar cell precursors without front and rear metallisation showed implied open-circuit voltages Voc values extracted from quasi-steady-state photoconductance (QSSPC) measurements above 680 mV. Fully finished solar cells with up to 20.0% energy conversion efficiency are presented. A fit of the cell's internal quantum efficiency using software tool PC1D and a comparison to a full-area aluminium-back surface field (Al-BSF) and thermal SiO2 is shown. PECVD-ONO was found to be clearly superior to Al-BSF. A separation of recombination at the metallised and the passivated area at the solar cell's rear is presented using the equations of Fischer and Kray. Nuclear reaction analysis (NRA) has been used to evaluate the hydrogen depth profile of the passivation layer system at different stages.

Surface Texturing of Crystalline Silicon Solar Cell Using Silicon Nanowires

2013 ◽  
Vol 52 (9R) ◽  
pp. 092301 ◽  
Author(s):  
Kyeom Seon Do ◽  
Min Gu Kang ◽  
Je Jun Park ◽  
Gi Hwan Kang ◽  
Jae-Min Myoung ◽  
...  
Keyword(s):  
Solar Cell ◽  
Silicon Nanowires ◽  
Silicon Solar Cell ◽  
Crystalline Silicon ◽  
Surface Texturing ◽  
Crystalline Silicon Solar Cell

Surface Texturing for Crystalline Silicon Solar Cell Using RIE Equipped with Metal-Mesh

2011 ◽  
Vol 328-330 ◽  
pp. 747-750 ◽  
Author(s):  
Dae Young Kong ◽  
Chan Seob Cho ◽  
Jun Hwan Jo ◽  
Bong Hwan Kim ◽  
Jong Hyun Lee
Keyword(s):  
Solar Cell ◽  
Silicon Wafer ◽  
Crystalline Silicon ◽  
Low Cost ◽  
Surface Texturing ◽  
Wafer Surface ◽  
Process Time ◽  
Black Silicon ◽  
Crystalline Silicon Solar Cell ◽  
Metal Mesh

Surface texturing is an important process to enhance light absorption and to improve efficiency of a solar cell. Reactive ion etching (RIE) process is a very effective process and low-cost process, which is applicable during the dry etching processes for thin crystalline silicon solar cells with large areas. In this study, we studied a dry and free mask texturing process on crystalline silicon wafer using SF6/O2plasmas and metal mesh in a RIE system, with special attention to the effect of the metal mesh and RIE conditions on the texture of the silicon surface. In particular, we have found an optimized RIE conditions by increasing the distance between the metal mesh and silicon wafer. We have also found that by increasing the RIE process time, with an optimized SF6/O2ratio, pressure and RF power, it is possible to switch from a random texture, to a nm-size pyramid texture and finally to an um-size pyramid texture. This RIE system textured a crystalline wafer surface that formed about 1~2 μm pyramidal black silicon with 7~10% of reflectivity.

scholarly journals Surface Passivation Studies on n+pp+ Bifacial Solar Cell

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Suhaila Sepeai ◽  
M. Y. Sulaiman ◽  
Kamaruzzaman Sopian ◽  
Saleem H. Zaidi
Keyword(s):  
Solar Cell ◽  
Screen Printing ◽  
Surface Passivation ◽  
Chemical Vapor ◽  
Front Surface ◽  
Back Surface ◽  
Antireflective Coatings ◽  
Solar Cell Performance ◽  
Sandwiched Structure ◽  
Bifacial Solar Cell

Bifacial solar cell is a specially designed solar cell for the production of electricity from both sides of the solar cell. It is an active field of research to make photovoltaics (PV) more competitive by increasing its efficiency and lowering its costs. We developed an n+pp+ structure for the bifacial solar cell. The fabrication used phosphorus-oxy-trichloride (POCl3) diffusion to form the emitter and Al diffusion using conventional screen printing to produce the back surface field (BSF). The n+pp+ bifacial solar cell was a sandwiched structure of antireflective coatings on both sides, Argentum (Ag) as a front contact and Argentum/Aluminum (Ag/Al) as a back contact. This paper reports the solar cell performance with different surface passivation or antireflecting coatings (ARC). Silicon nitride (SiN) deposited by Plasma-Enhanced Chemical Vapor Deposition (PECVD), thermally grown silicon dioxide (SiO2), PECVD-SiO2, and SiO2/SiN stack were used as ARC. The efficiency obtained for the best bifacial solar cell having SiN as the ARC is 8.32% for front surface illumination and 3.21% for back surface illumination.

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