Comparison of diffused layer prepared using liquid dopant solutions and pastes for solar cell with screen printed electrodes

Abstract

Purpose The purpose of this study is comparison of the diffusion processes performed using the commercial available dopant paste made by Filmtronics and the original prepared liquid dopant solution. To decrease prices of industrially produced silicon-based solar cells, the new low-cost production processes are necessary. The main components of most popular silicon solar cells are with diffused emitter layer, passivation, anti-reflective layers and metal electrodes. This type of cells is prepared usually using phosphorus oxychloride diffusion source and metal pastes for screen printing. The diffusion process in diffusion furnace with quartz tube is slow, complicated and requires expensive equipment. The alternative for this technology is very fast in-line processing using the belt furnaces as an equipment. This approach requires different dopant sources. Design/methodology/approach In this work, the diffusion processes were made for two different types of dopant sources. The first one was the commercial available dopant paste from Filmtronics and the second one was the original prepared liquid dopant solution. The investigation was focused on dopant sources fabrication and diffusion processes. The doping solution was made in two stages. In the first stage, a base solution (without dopants) was made: dropwise deionized (DI) water and ethyl alcohol were added to a solution consisting of tetraethoxysilane (TEOS) and 99.8 per cent ethyl alcohol. Next, to the base solution, orthophosphoric acid dissolved in ethyl alcohol was added. Findings Diffused emitter layers with sheet resistance around 60 Ω/sq were produced on solar grade monocrystalline silicon wafers using two types of dopant sources. Originality/value In this work, the diffusion processes were made for two different types of dopant sources. The first one was the commercial available dopant paste from Filmtronics and the second one was the original prepared liquid dopant solution.

Spray-on glass solution for fabrication silicon solar cell emitter layer

“…The source of phosphorus atoms for the doping solution, as in (Bouhafs et al , 2006; Drabczyk et al , 2016; Ochoa-Martınez et al , 2014; Yadav et al , 2015), was orthophosphoric acid. The 3.0 cm 3 of phosphoric acid (H 3 PO 4 ) was dissolved in 16.7 cm 3 of 99.8 per cent ethyl alcohol forming the component solution named CS3 (Figure 4).…”

Borosilicate spray-on glass solutions for fabrication silicon solar cell back surface field

“…Effectivity of boron silica glass removal process was rated by checking whether or not traces of it remained on wafer surface. The images analysis suggests that a big advantage of developed dopant solutions is that after the diffusion process the glass is easy to remove; similarly, as in the case of phosphorous, silica glass removal described in Drabczyk et al (2016b). The sample SEM image of tested wafers surface is shown in Figure 10.…”

The influence of emitter resistance on the electrical parameters of mono- and multicrystalline silicon solar cells

“…Finally, wrongly selected N A and t result in both a reduction short circuit current (I sc ) and open circuit voltage (U oc ) (Goetzberger et al, 1998). An interesting alternative to the source of POCl 3 admixture may be liquid sources of admixture based on tetraethoxysilane and orthophosphoric acid (Drabczyk et al, 2016;Filipowski et al, 2017). They allow the creation of an emitter layer with a surface resistance in the range of 20-100 X/h.…”