Ultra Thin Coating Aids in Photodetector Research


Researchers at Pennsylvania State University have released a study that seeks to further advance photodetectors’ use by integrating the technology with durable Gorilla glass, the material used for smart phone screens.

A few challenges stand in the way, however, and reportedly researchers have determined that one remedy is that the chemical compound molybdenum disulfide is the best material to use as a coating on the glass.

The research was recently published in the journal ACS Nano.

The Study

Also known as photosensors, photodetectors convert light energy into electrical signals to complete tasks such as opening automatic sliding doors and automatically adjusting a cell phone’s screen brightness in different lighting conditions.

“There are two problems to address when attempting to manufacture and scale photodetectors on glass,” said principal investigator Saptarshi Das, assistant professor of engineering science and mechanics.

“It must be done using relatively low temperatures, as the glass degrades at high temperatures, and must ensure the photodetector can operate on glass using minimal energy.”

That first challenge led Das, along with ESM doctoral student Joseph R. Nasr, to the molybdenum disulfide coating. (Mark W. Horn, professor of ESM, and Aaryan Oberoi, ESM doctoral student, also participated in this project.)

Then, according to Penn State, Joshua Robinson, professor of materials science and engineering, and MatSE doctoral student Nicholas Simonson, used a chemical reactor at 600 degrees Celsius to fuse together the compound and glass.

The next step was to turn the glass and coating into a photodetector by patterning it using a conventional electron beam lithography tool.

“We then tested the glass using green LED lighting, which mimics a more natural lighting source unlike laser lighting, which is commonly used in similar optoelectronics research,” Nasr said.

According to the researchers, the ultra-thin body of the molybdenum disulfide photodetectors allows for better electrostatic control, and ensures it can operate with low power.

If developed commercially, the smart glass could lead to advances in other sectors including in manufacturing, civil infrastructure, energy, health care, transportation and aerospace engineering, according to the researchers. The technology could be applied in biomedical imaging, security surveillance, environmental sensing, optical communication, night vision, motion detection and collision avoidance systems for autonomous vehicles and robots.

“Smart glass on car windshields could adapt to oncoming high-beam headlights when driving at night by automatically shifting its opacity using the technology,” Robinson said. “And new Boeing 757 planes could utilize the glass on their windows for pilots and passengers to automatically dim sunlight.”

Corning Incorporated and the Center for Atomically Thin Multifunctional Coatings, housed in Penn State’s Materials Research Institute, funded this research.


Tagged categories: Coatings Technology; Coatings Technology; Glass coatings; NA; North America; Research and development

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