Solving The Silicon-Perovskite Tandem Solar Cell Puzzle

Join daily news updates from CleanTechnica on e-mail. Or follow us on Google News!

Tandem silicon-perovskite photo voltaic cells mix the acquainted silicon PV know-how with the not-so-familiar materials perovskite, and so they have been grabbing consideration for his or her potential to ship extra photo voltaic vitality over a smaller space, at much less price. So, what’s to not like a couple of tandem photo voltaic cell? Finish-of-life questions are one key space below exploration, and options are rising.

Perovskites & The Tandem Photo voltaic Cell Revolution

A silicon-perovskite tandem photo voltaic cell combines the perfect of each photovoltaic worlds. Silicon has set the gold commonplace for commercial-scale photo voltaic conversion effectivity, however silicon is pricey relative to different photovoltaic supplies. Perovskite has a decrease conversion effectivity but it surely yields a inexpensive photo voltaic cell, partly as a result of it’s extra amenable to high volume, low cost manufacturing methods than silicon (see extra perovskite background here).

Perovskite is a finicky materials by itself, so combining it with silicon in a tandem photo voltaic cell can convey down the general price of a photo voltaic cell whereas reaching a excessive degree of photo voltaic conversion effectivity. Some PV stakeholders are already pursuing the tandem photo voltaic cell path to commercialization, one instance being the UK firm Oxford PV.

Chasing The Tandem Photo voltaic Cell Past The Schockley-Queisser Border, Or Not

The speedy progress of tandem photo voltaic cell R&D was underscored final 12 months, when the Chinese language agency LONGi introduced a brand new tandem photo voltaic cell with a record-breaking solar conversion efficiency of 33.9%. The 33.9% determine is critical as a result of it edges previous the theoretical restrict for photo voltaic conversion effectivity in a silicon photo voltaic cell. The restrict been established at 33.7% primarily based on calculations by photo voltaic researchers William Shockley and Hans-Joachim Queisser again in 1961.

When it comes to commercialization, although, one over-arching query is the price of manufacturing. Probably the most environment friendly tandem photo voltaic cell shouldn’t be essentially probably the most aggressive one to supply. The rising round economic system additionally must be considered. That features the sustainability of the fabric provide chain and the manufacturing course of together with end-of-life remedies.

A multi-branched crew on the main German photo voltaic analysis establishment Fraunhofer has been engaged in a soup-to-nuts evaluation of probably the most aggressive pathways for commercial-scale improvement of a silicon-perovskite tandem photo voltaic cell, below the considerably awkward title of “MaNiTU.” Their conclusion, launched final week, signifies that breaking the Shockley-Queisser barrier is a neat trick however not essentially probably the most commercially viable one.

With the present state of business know-how in thoughts, the researchers developed a brand new perovskite-silicon tandem photo voltaic cell together with a bespoke manufacturing course of geared toward teasing photo voltaic conversion effectivity up whereas containing provide chain and manufacturing prices. They concluded that a solar conversion efficiency of 31.6% presents probably the most viable and sustainable pathway to mass adoption for high-efficiency tandem photo voltaic cells.

Sustainability & The Silicon-Perovskite Tandem Photo voltaic Cell Of The Future

The sustainability angle is an important one as a result of the Fraunhofer crew advocates for a tandem photo voltaic cell that deploys a perovskite system primarily based on lead, a fabric generally used within the perovskite area as a stabilizer. The Fraunhofer crew additionally examined non-leaded perovskite formulation, however concluded that none have been commercially viable at the moment.

“The research team was unable to produce tandem solar cells of sufficient efficiency from any of the lead-free materials that they theoretically and experimentally analyzed, however, as the intrinsic material qualities were simply not high enough,” Fraunhofer defined in a press launch dated December 11.

Lead was as soon as a key ingredient in lots of shopper merchandise together with gasoline, home paint, toys, and dishware. It has been banned or considerably lowered for these and different makes use of right here within the US, notably in use instances the place human publicity and environmental leaching is a danger.

These dangers aren’t current in a tandem photo voltaic cell. For that matter, the US Environmental Safety Company notes that lead continues to be used generally used to supply sheet metals and different alloys. Lead additionally performs a ubiquitous function in electronics manufacturing, and battery producers additionally proceed to make use of lead, one instance being the lead-acid batteries utilized in virtually each gas-powered car on the street.

Recycling & The Round Financial system

As a key a part of the MaNiTU challenge, the Fraunhofer crew developed a lifecycle evaluation of their 31.6% environment friendly tandem photo voltaic cell, which decided that “advanced recycling processes” would assist lifecycle vitality effectivity. The press launch didn’t embody particulars, so I’m reaching out to the establishment for extra info. Within the meantime, different researchers have additionally been growing perovskite recycling options.

“When it comes to perovskite solar modules that contain toxic and water soluble lead, going to landfill is not an option due to its threat to ecosystem and human health,” be aware the authors of a 2021 research that explored a recycling resolution that mixes a warmth remedy to de-laminate perovskite movies, together with a carboxylic acid cation-exchange resin adsorbent to seize the lead ions.

“Different from previous lead-trapping studies via strongly acidic cation-exchange resin, the weakly acidic cation-exchange resin showed better lead recycling efficiency due to easy release of Pb²⁺ ions from carboxylic acid functional group compared with sulfonic acid,” the researchers emphasised.

The Lead-Free Tandem Photo voltaic Cell Of The Future

Final spring, a analysis crew in The Netherlands issued detailed lifecycle comparison between a tandem photo voltaic cell and a silicon-only photo voltaic cell that gives some additional insights. The research included recovering silicon and silver from the tandem photo voltaic cells in addition to lead. “Climate change impacts per kilowatt hour were projected to decrease by two-thirds over time,” the researchers concluded, whereas noting that the general outcomes would rely on the power of tandem photo voltaic cells that to outlast their silicon-only counterparts.

Within the meantime, the seek for a lead-free different continues. Tin has emerged as one possible pathway to lead-free perovskitesbecause it occupies the identical house on the periodic desk. The thought first crossed the CleanTechnica radar again in 2014. Catching up in January of this 12 months, we discover that researchers are starting to unlock the secrets and techniques of rising tin perovskite crystals.

One other lead-adjacent aspect, bismuth, has additionally been the topic of research. Final spring a analysis crew in China synthesized a lead-free CsBiSCl₂ perovskite formula to be used as a photo voltaic vitality harvester. They concluded that the soundness issue was promising sufficient to warrant additional exploration, so maintain a watch open for extra on the bismuth facet.

Comply with me through LinkTreeor @tinamcasey on LinkedIn and Bluesky.

Photograph (cropped): Researchers have designed a brand new silicon-perovskite tandem photo voltaic cell to maximize solar conversion efficiency and lifecycle sustainability collectively (courtesy of Fraunhofer).