In work published in the National Science Review (nwaa288), a team at HPSTAR led by Dr. Xujie Lu applied high pressure to tune the remarkable photoluminescence (PL) properties in halide perovskites. For the first time, they reveal a universal relationship whereby regulating the level of off-centering distortion (towards 0.2) can achieve optimal PL performance.

The extraordinary electronic and optical properties that halide perovskites possess have revolutionized next-generation photovoltaics and optoelectronics' prospects. However, the underlying mechanisms responsible for their unique functionalities are still not fully understood. Developing our fundamental understanding of how structural configurations affect their properties is crucial. As a thermodynamic variable, pressure can effectively tune the lattice and electronic configurations, resulting in concomitant changes in materials' properties.

Using advanced in situ/operando high-pressure techniques in combination with theoretical calculations yielded fascinating results. "By carefully selecting and regulating the highly-distorted halide perovskites, we reached an otherwise unreachable structural region for probing properties that affords a great opportunity to understand the structure-property relationship," said Dr. Lu.

The team applied their obtained principle as a guideline to achieve bright PL in (CH3NH3)1-xCsxGeI3 by chemically substituting CH3NH3+ with smaller sized Cs+. The chemical substitution tunes the distortion, much like external pressure. The compression of CsGeI3 further regulates the distortion to the optimal value at 0.7 GPa, which maximizes the emission with a ten-fold enhancement. These findings open new paths to high-performance optoelectronic materials by leveraging the distortion and strain degrees of freedom.

"This work not only demonstrates the quantitative relationship between structural distortion and the PL property of halide perovskites," said Dr. Lu. "But also illustrates the use of the extracted knowledge for the virtuous cycle of materials design and optimization."

This direct use of knowledge gained from high-pressure research to purposefully design and synthesize materials with desired properties at ambient conditions is rarely reported.

Research Report: "Regulating off-centering distortion maximizes photoluminescence in halide perovskites"

Related Links
Center For High Pressure Science and Technology Advanced Research
All About Solar Energy at SolarDaily.com

Tweet

Thanks for being here; We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain. With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords. Our news coverage takes time and effort to publish 365 days a year. If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Contributor $5 Billed Once credit card or paypal		SpaceDaily Monthly Supporter $5 Billed Monthly paypal only

Ecoppia Signed Another Significant Project Of 450MW With Solar Leader Azure Power
Herzeliya, Israel (SPX) Dec 16, 2020
Ecoppia, a pioneer in robotic solutions for photovoltaic solar, reports yet another significant project of 450MW signed in October with Azure Power, the renowned solar energy player. The project is now reaching advanced stages, scheduled to go live on the beginning of Q1 2021. Despite the ongoing global pandemic, Ecoppia secured new projects for more than 10GW in the last four quarters, maintaining a compound annual growth rate (CAGR) of more than 280% in the last six years. Without any phys ... read more