Specialized crystalline films revealed to be highly conductive and transparent

August 18, 2015, Pacific Northwest National Laboratory
Specialized crystalline films revealed to be highly conductive and transparent
SrTiO3(001) heterojunction. The Sr0.12La0.88CrO3 conducts holes and the SrTiO3 conducts electrons. When particles of sunlight (photons) are absorbed in the material, an electron and a hole are created, and they move to opposite sides of the junction: the electron to the SrTiO3 and the hole to the Sr0.12La0.88CrO3. If the junction is connected to an electrical circuit, the electricity created by the light can be used for electrical power (solar cell application), or to detect the incoming light (photodetector application).

The performance of solar cells, flat panel displays, and other electronics are limited by today's materials. A new material, created by modifying a transparent insulating oxide, replacing up to 25 percent of the lanthanum ions in the host material with strontium ions, offers considerable promise. The new perovskite film, with the formula SrxLa1-xCrO3, (x up to 0.25), conducts electricity more effectively than the unmodified oxide and yet retains much of the transparency to visible light exhibited by the pure material.

Materials that are both electrically conductive and optically transparent are needed for more efficient solar cells, light detectors, and several kinds of electronic devices that are by nature transparent to . Of particular importance are new materials that conduct electricity by using missing electrons, otherwise known as "holes." The new perovskite film falls into this category.

The development of high-performance transparent conducting oxides (TCOs) is critical to many technologies ranging from to . Although electron conducting (n-type) TCOs are presently in use in many devices, their hole-conducting (p-type) counterparts have not been commercialized as candidate materials because they exhibit much lower conductivities. Scientists at Pacific Northwest National Laboratory along with collaborators at Binghamton University and the Paul Drude Institute in Berlin show that La1-xSrxCrO3 (LSCO) is a new p-type TCO with considerable potential. The researchers demonstrate that crystalline LSCO films deposited on SrTiO3(001) by show figures of merit which are highly competitive with best p-type TCOs reported to date, and yet are more stable and structurally compatible with the workhorse materials of oxide electronics, as seen in the image. Being structurally and chemically compatible with other perovskite oxides, perovksite LSCO offers considerable promise in the design of all-perovskite oxide electronics.

Explore further: New research to improve solar cells

More information: "Hole-Induced Insulator-to-Metal Transition in La1-xSrxCrO3 Epitaxial Films." Physical Review B 91:155129. DOI: 10.1103/PhysRevB.91.155129

Related Stories

New research to improve solar cells

August 13, 2015

New research from Professors Saiful Islam and Aron Walsh could lead to more efficient solar cells. The work appears in the leading journal Nature Communications.

New conductive coatings for flexible touchscreens

January 21, 2015

Mobile phones and smart phones still haven't been adapted to the carrying habits of their users. That much is clear to anyone who has tried sitting down with a mobile phone in their back pocket: the displays of the innumerable ...

Researchers enable solar cells to use more sunlight

February 25, 2015

Scientists of the University of Luxembourg and of the Japanese electronics company TDK report progress in photovoltaic research: they have improved a component that will enable solar cells to use more energy of the sun and ...

Simulations for better transparent oxide layers

September 1, 2014

Touchscreens and solar cells rely on special oxide layers. However, errors in the layers' atomic structure impair not only their transparency, but also their conductivity. Using atomic models, Fraunhofer researchers have ...

Recommended for you

EPA adviser is promoting harmful ideas, scientists say

March 22, 2019

The Trump administration's reliance on industry-funded environmental specialists is again coming under fire, this time by researchers who say that Louis Anthony "Tony" Cox Jr., who leads a key Environmental Protection Agency ...

Coffee-based colloids for direct solar absorption

March 22, 2019

Solar energy is one of the most promising resources to help reduce fossil fuel consumption and mitigate greenhouse gas emissions to power a sustainable future. Devices presently in use to convert solar energy into thermal ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.