Collaborative Research: Chalcogenide Perovskite Light Emitting Diodes to Fill the Green Gap

Solid-state lighting plays a central role in substantially reducing the amount of energy consumption. The efficiency of current LEDs drastically decreases from ∼80% in the blue-light regions to ∼15% in the green region. This lack of a suitable semiconductor green light source is known as the “green gap” problem.

This research aims to address this problem by developing green LEDs based on an entirely new family of semiconductor materials called chalcogenide perovskite. The proposed work is a critical step towards opening a new frontier in semiconductor device research based on chalcogenide perovskites, with far reaching impacts on applications such as sensing, energy harvesting, information processing, and storage.

The use of earth-abundant elements in these materials can reduce our nation’s reliance on rare-earth materials. Through collaboration with local industry, the proposed work will also develop samples and instrumentation for advanced laboratory courses, which will not only impact STEM education in the US and worldwide, but also the local economy in Western New York.

The research activities involving machine learning, first-principles computation, material synthesis, device fabrication, and characterization, will offer important interdisciplinary training to a broad student body.

This proposal aims to demonstrate the first chalcogenide perovskite-based light emitting diodes, with the long-term goal of bridging the green gap in LED technology. This will involve an iterative process in which theoretical prediction will guide material synthesis and atomic level structural, optical, and carrier transport characterization will inform theoretical models as well as device design and fabrication.

The idea of this work was conceived based on the principal investigators' recent prediction and realization of chalcogenide perovskite materials with tunable band gap and promising semiconducting properties. The specific project objectives are to: i) Develop a low temperature chalcogenide perovskite thin-film processing technique compatible with device fabrication and growing high quality SrHfS3 and SrZrS3 thin films with strong green and amber light emission. ii) Control device properties through concerted first-principles computation and experiments of atomic scale structural, optical, and carrier transport characteristic. iii) Design, fabricate, and evaluate green and amber LEDs from n- and p- type doped SrHfS3 and SrZrS3 thin films.

An innovative device fabrication technique incorporating micro-transfer-printing allows for dissimilar materials to form a high-quality p-i-n type LED structure with extremely clean interfaces without being constrained by their growth conditions.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.