The majority of talks, posters, and papers proposed for the conference are on the subject of perovskite—so exciting is the field even though perovskite isn’t technically a dye cell
A new solar material that has the same crystal structure as a mineral first found in the Ural Mountains in 1839 is shooting up the efficiency charts faster than almost anything researchers have seen before—and it is generating optimism that a less expensive way of using sunlight to generate electricity may be in our planet’s future.
Researchers at the Energy Department’s National Renewable Energy Laboratory (NREL) are analyzing the new material, perovskite, using the lab’s unique testing capabilities and broad spectrum of expertise to uncover the secrets and potential of the semiconducting cube-like mineral.
NREL has already produced three scientific papers on perovskite (see sidebar), reporting on the science behind the very large length of the electron pairs (or charge diffusion length) in mesostructured perovskite solar cells. The two most-studied perovskite device structures are mesostructured (of medium complexity) and planar (two-dimensional). NREL Research Fellow David Ginley, who is a world-renowned materials scientist and winner of several R&D 100 Awards, said what makes perovskite device structures so remarkable is that when processed in a liquid solution, they have unusual abilities to diffuse photons a long distance through the cell. That makes it far less likely that the electrons will recombine with their hole pairs and be lost to useful electricity. And that indicates a potential for low-cost, high-efficiency devices.
NREL Senior Scientist Daniel Friedman notes that the light-absorbing perovskite cells have “a diffusion length 10 times longer than their absorption length,” not only an unusual phenomenon, but a very useful one, too.
Perovskite Is Flexible, Easier to Manipulate
The new cells are made from a relative of the perovskite mineral found in the Ural Mountains. Small but vital changes to the material allow it to absorb sunlight very efficiently. The material is also easy to fabricate using liquids that could be printed on substrates like ink in a printing press, or made from simple evaporation. These properties suggest an easy, affordable route to solar cells.
By playing with the elemental composition, it is also possible to tune the perovskite material to access different parts of the sun’s spectrum. That flexibility can be crucial, because it means that the material can be changed by deliberately introducing impurities, and in such a way that it can be used in multijunction solar cells that have ultra-high efficiencies. Multijunction solar cells are an NREL invention from 1991, but because of high material costs, standard multijunctions are used mostly in outer space applications such as satellites and the Mars rovers. Cheaper multijunction cells based on perovskites could radically change this.
In four years, perovskite’s conversion efficiency—the yield at which the photons that hit the material are turned into electrons that can be used to generate electricity—has grown from 3.8% in 2009 to just north of 16%, with unconfirmed reports of even higher efficiencies arriving regularly. That’s better than a four-fold increase. By contrast, efficiencies of single-crystal solar cells grew by less than 50% during their first five years of development, and most other types of solar cells showed similar modest improvements during their first few years.
NREL materials scientists are encouraged by the possibility of further optimizing the materials. For example, replacing lead with tin in the cells could improve the efficiency of multijunction cells made from perovskite. Besides switching to a more environmentally friendly material, the change from lead to tin would also allow the finished solar cell to better withstand high humidity.
The Latest on: Perovskite
via Google News
The Latest on: Perovskite
- Pressure-regulated excitonic feature enhances photocurrent of all-inorganic 2D perovskiteon March 3, 2021 at 10:58 pm
We report significantly enhanced photocurrents in the all-inorganic 2D perovskite Cs2PbI2Cl2, achieving over 3 orders of magnitude increase at the industrially achievable level of 2 GPa in comparison ...
- Hunt Perovskite Technologies Continues to Expand Patent Portfolioon March 2, 2021 at 9:09 am
Hunt Perovskite Technologies (HPT) today announced that the United States Patent and Trademark Office (USPTO) has granted HPT two additional patents related to its ongoing work in the development of ...
- A common optical approach to thickness optimization in polymer and perovskite solar cellson March 2, 2021 at 2:56 am
The structure of experimentally designed solar cells was optimized in terms of the photoactive layer thickness for both organic bulk heterojunction and hybrid perovskite solar cells. The photoactive ...
- Spontaneously coherent orbital coupling of counterrotating exciton polaritons in annular perovskite microcavities | Light: Science & Applicationson March 1, 2021 at 3:17 pm
By engineering artificial annular potential landscapes in halide perovskite semiconductor microcavities, we experimentally and theoretically demonstrate the room-temperature spontaneous formation of a ...
- MIT researchers improve perovskite-based solar panel efficiencyon March 1, 2021 at 3:03 am
Today, solar panels are typically made of silicon, but in the future, they could be manufactured from a different material that offers more efficiency and lower manufacturing cost. The material ...
- Perovskite solar cell with cesium-titanium dioxide nanotubeson March 1, 2021 at 12:41 am
An international research group has developed a perovskite solar cell with strong thermal stability and enhanced electron injection by using special nanotubes made of cesium-titanium dioxide (Cs ...
- Metal-perovskite-metal back contact solar cell with 4.31% efficiencyon February 26, 2021 at 12:51 am
Researchers at Chitkara University in the Indian state of Punjab have proposed an electrostatically-doped back-contact design for perovskite-based solar cells that overcomes the fabrication and ...
- Response to Comment on “Resolving spatial and energetic distributions of trap states in metal halide perovskite solar cells”on February 25, 2021 at 1:17 pm
(A) Normalized C-V curves of a Si diode (red), perovskite thin single crystal (PVK crystal) (blue), and polycrystalline thin film (PVK film) (green and khaki) solar cells measured at ac frequency (ω) ...
- Comment on “Resolving spatial and energetic distributions of trap states in metal halide perovskite solar cells”on February 25, 2021 at 12:37 pm
From electrostatic arguments, we show that the results are not trap densities but are a consequence of the geometrical capacitance and charge injection into the perovskite layer. Despite the excellent ...
- Researchers improve efficiency of next-generation solar cell materialon February 24, 2021 at 8:01 am
Now, a new approach to the design of perovskite cells has pushed the material to match or exceed the efficiency of today’s typical silicon cell, which generally ranges from 20 to 22 percent, laying ...
via Bing News