Towards high-efficiency skinny crystalline silicon photo voltaic cells
by Employees Writers
Washington DC (SPX) Oct 02, 2023
Solar energy has change into indispensable in our international pursuit of unpolluted power and sustainability. Right this moment, about 95 p.c of photo voltaic cells are made utilizing crystalline silicon (c-Si). Most industrial designs make use of a c-Si photoactive layer with a thickness of round 160-170 um. Nonetheless, since silicon alone makes up almost half the price of every photo voltaic panel, consultants consider that next-generation c-Si photo voltaic cells shall be a lot thinner.
Sadly, regardless of a number of latest enhancements, the conversion effectivity of skinny c-Si photo voltaic cells nonetheless lags far behind that of thick industrial ones. This downside stems from the truth that the most effective design methods for skinny c-Si cells solely maximize particular person parameters, comparable to short-circuit present density, open-circuit voltage, or fill issue. None of the present strategies can concurrently enhance these parameters, all of that are vital for realizing excessive effectivity.
Towards this backdrop, a analysis crew from Hangzhou Dianzi College, China, has developed a brand new technique to attain exceptional effectivity enhancements in skinny c-Si photo voltaic cells. Their research, printed the Journal of Photonics for Vitality (JPE), represents a big breakthrough within the area of silicon photo voltaic cell know-how.
The proposed technique optimizes a number of key optical and electrical traits, which the crew recognized to be answerable for the variations within the reported conversion efficiencies of thick and skinny c-Si photo voltaic cells. Utilizing industrial software program applications, they ran optical simulations of varied skinny cell designs. By additional experiments utilizing photo voltaic cells, the researchers arrived at an progressive fabrication methodology that gives a number of benefits over standard methods.
As a substitute of utilizing the silicon ingot chopping strategy sometimes used to fabricate thick c-Si layers, the crew employed a layer switch methodology. They used hydrofluoric acid to etch pores right into a thick silicon wafer. This porous layer served as a substrate to develop a 20-um-thin monocrystalline silicon layer, which may very well be simply indifferent and transferred onto a versatile stainless-steel substrate.
To reinforce the optical and electrical efficiency of the skinny silicon layer, the researchers deposited a number of steel nanofilms on either side utilizing plasma-enhanced chemical vapor deposition-SiO2/SiNx/SiOx layers and Al2O3/SiNx/SiOx layers with a pyramidal texture on the perimeters dealing with the entrance and rear of the photo voltaic cell, respectively.
The entrance SiNx/SiOx and rear SiOx/SiNx layers elevated the sunshine absorption of the silicon layer within the shorter and longer wavelengths, respectively. This, in flip, enhanced the short-circuit present density-a measure of the variety of cost carriers that may be generated and picked up by the photo voltaic cell. In contrast with a regular photo voltaic cell used as reference, the present density elevated from 34.3 to 38.2 mA/cm2.
Moreover, the SiO2 and Al2O3 layers offered excessive floor passivation, minimizing the recombination and lack of generated cost carriers. This led to a better open-circuit voltage-a measure of the utmost voltage generated by a photo voltaic cell. It was boosted from 632 mV within the reference cell to 684 mV when utilizing the proposed design. Consequently, the fill issue of the photo voltaic cell, an indicator of how shut a photo voltaic cell operates to its theoretical most effectivity, elevated from 76.2 to 80.8 p.c.
As confirmed by each simulations and experiments, the proposed technique resulted in an enhancement of conversion effectivity from 16.5 to 21.1 p.c, a exceptional acquire of 4.6 p.c (similar to an roughly 28 p.c enchancment, in comparison with the reference cell). This places the effectivity of skinny c-Si photo voltaic cells near that of their industrial thick counterparts, which immediately clocks in at 24 p.c.
JPE Affiliate Editor Leonidas Palilis, Professor of Condensed Matter Physics at College of Patras, Greece, remarks, “General, the findings of this research current a novel strategy to notice high-performance skinny crystalline silicon photo voltaic cells utilizing a lot much less silicon-for a 20-um cell, round one eighth of the quantity required for a thick 160-um cell on a given panel dimension.” This advance will doubtless contribute to extra widespread cost-effective adoption of silicon solar energy know-how, as a result of lowered value and the concomitant enlargement of the photo voltaic panel manufacturing capability.
Analysis Report:Investigation on important effectivity enhancement of skinny crystalline silicon photo voltaic cells
Associated Hyperlinks
Worldwide Society for Optics and Photonics
All About Photo voltaic Vitality at SolarDaily.com
