Nav: Home

New records in perovskite-silicon tandem solar cells through improved light management

November 12, 2018

Tandem solar cells made of silicon and metal halide perovskite compounds can convert a particularly large portion of the solar spectrum into electrical energy. However, part of the light is reflected and is thus lost for purposes of energy conversion. Using nanostructures, the reflection can be reduced significantly ensuring that the solar cell captures more light. For example, pyramid-shaped microfeatures can be etched into silicon. However, these features cause microscopic roughness in the silicon surface, making it no longer suitable as a substrate for deposition of extremely thin perovskite layers. This is because perovskites are normally deposited to a polished wafer using solution processing to form an extremely thin film, much thinner than the pyramidal features. A rough-etched silicon surface layer therefore prevents formation of a uniform conformal layer.

Efficiency improved from 23,4 % to 25.5 %

A team headed by HZB physicist Steve Albrecht has investigated an alternative approach of light management with textures in tandem solar cells. The team fabricated an efficient perovskite/silicon tandem device whose silicon layer was etched on the back-side. The perovskite layer could be applied by spincoating onto the smooth front-side of the silicon. The team afterwards applied a polymer light management (LM) foil to the front-side of the device. This enabled processing of a high-quality perovskite film on a flat surface, while still benefiting from the front-side texture. "In this way, we succeeded in considerably improving the efficiency of a monolithic perovskite-silicon heterojunction tandem cell from 23.4 % to 25.5 %", says Marko Jošt, first author of the study and postdoctoral fellow in Albrecht's team.

Numerical model shows possibility for up to 32.5 %

In addition, Jošt and colleagues have developed a sophisticated numerical model for complex 3D features and their interaction with light. This enabled the team to calculate how different device designs with textures at various interfaces affect efficiency. "Based on these complex simulations and empirical data, we believe that an efficiency of 32.5 % can realistically be achieved - if we succeed to incorporate high quality perovskites with a band gap of 1.66 eV", says Jošt.

Suitable for building integrated PV

And team leader Steve Albrecht adds: "Based on real weather data, we were able to calculate the energy yield over the course of a year - for the different cell designs and for three different locations." In addition, the simulations show that the LM foil on the front-side of the solar cell device is particularly advantageous under diffuse light irradiation, i.e. not only under perpendicularly incident light. Tandem solar cells with the new LM foil could therefore also be suitable for incorporation in building-integrated photovoltaics (BIPV), opening up huge new areas for energy generation from large sky scraper facades.
-end-


Helmholtz-Zentrum Berlin für Materialien und Energie

Related Silicon Articles:

To e-, or not to e-, the question for the exotic 'Si-III' phase of silicon
It would be difficult to overestimate the importance of silicon when it comes to computing, solar energy, and other technological applications.
Polymer-coated silicon nanosheets -- an alternative to graphene
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene.
Bringing silicon to life
Living organisms have been persuaded to make chemical bonds not found in nature, a finding that may change how medicines and other chemicals are made in the future.
Bringing carbon-silicon bonds to life
Following a few tweaks, heme proteins can efficiently catalyze the formation of carbon-silicon bonds, which are not found in any known biological molecules, nor capable of being created through any existing biological processes.
What a twist: Silicon nanoantennas turn light around
Scientists at MIPT and their colleagues from ITMO University and the University of Texas at Austin have developed a nonlinear nanoantenna that can be used to scatter light in a desired direction by varying its intensity.
Obtaining of silicon nanowires becomes eco-friendly
Scientists from the Faculty of Physics, the Lomonosov Moscow State University have devised a technique of silicon nanowires synthesis.
Recharging on stable, amorphous silicon
Next-generation anodes for lithium ion batteries will probably no longer be made of graphite.
More stable qubits in perfectly normal silicon
The power of future quantum computers stems from the use of qubits, or quantum bits.
Silicon nanoparticles trained to juggle light
Silicon nanoparticles based devices would allow to transmit, reflect, or scatter incident light in a specified direction, depending on its intensity.
New silicon structures could make better biointerfaces
A team of researchers have engineered silicon particles one-fiftieth the width of a human hair, which could lead to 'biointerface' systems designed to make nerve cells fire and heart cells beat.

Related Silicon Reading:

Bad Blood: Secrets and Lies in a Silicon Valley Startup
by John Carreyrou (Author)

AI Superpowers: China, Silicon Valley, and the New World Order
by Kai-Fu Lee (Author)

Silicon States: The Power and Politics of Big Tech and What It Means for Our Future
by Lucie Greene (Author)

Valley of Genius: The Uncensored History of Silicon Valley (As Told by the Hackers, Founders, and Freaks Who Made It Boom)
by Adam Fisher (Author)

Silicon Photonics Design: From Devices to Systems
by Lukas Chrostowski (Author), Michael Hochberg (Author)

Sophia of Silicon Valley: A Novel
by Anna Yen (Author)

Brotopia: Breaking Up the Boys' Club of Silicon Valley
by Emily Chang (Author)

Silicon City: San Francisco in the Long Shadow of the Valley
by Cary McClelland (Author)

Anti-Drop iPhone 8 Plus / 7 Plus (5.5Inch) Liquid Silicone Gel Case, TOSHIELD Soft Microfiber Cloth Lining Cushion for iPhone 8 Plus and 7Plus (Yellow 1)
by TOSHIELD (Publisher)

Troublemakers: Silicon Valley's Coming of Age
by Simon & Schuster

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Bias And Perception
How does bias distort our thinking, our listening, our beliefs... and even our search results? How can we fight it? This hour, TED speakers explore ideas about the unconscious biases that shape us. Guests include writer and broadcaster Yassmin Abdel-Magied, climatologist J. Marshall Shepherd, journalist Andreas Ekström, and experimental psychologist Tony Salvador.
Now Playing: Science for the People

#513 Dinosaur Tails
This week: dinosaurs! We're discussing dinosaur tails, bipedalism, paleontology public outreach, dinosaur MOOCs, and other neat dinosaur related things with Dr. Scott Persons from the University of Alberta, who is also the author of the book "Dinosaurs of the Alberta Badlands".