EPSCoR Research Fellows: NSF: Integrated Photonic Platforms Empowered by Solution-Processed Wide-Bandgap Perovskites

Integrated Photonics, encompassing functional devices like light-emitting diodes (LEDs) and lasers, waveguides, filters, modulators, and photodetectors miniaturized onto a single chip, holds transformative and revolutionary impacts on signal sensing, processing, and communication. This EPSCoR Research Fellows project focuses on a family of emerging wide-bandgap crystals, namely layered cesium lead halide perovskites, and explores their potential in integrated photonics.

Supported by the Fellowship program, the principal investigator (PI) and her graduate student from the University of Nebraska-Lincoln (UNL) will carry out the project via extended visits and collaboration with researchers at the National Institute of Standards and Technology (NIST). The successful implementation of the proposed research will not only advance the understanding of the crystal growth and patterning synthesis of wide-bandgap perovskites from solution processes, but also empower cost-effective integrated photonic platforms that can be utilized for future exploration of light-matter interaction in both classical and quantum regimes.

Moreover, the Fellowship will provide unique opportunities for an Assistant Professor and her graduate student to access the world-class cleanroom and nanofabrication facilities at NIST, to establish long-term collaboration between UNL and NIST, and thus to shape PI’s career trajectory and the quantum research and education landscape at UNL and Nebraska Jurisdiction.

This Fellowship project aims to transform the field of integrated photonics through interdisciplinary research on wide-bandgap (WBG) cesium lead halide perovskites (CLHPs) and their device design and fabrication to realize high-quality photonic devices in a cost-effective manner. Distinguishing from conventional WBG materials (e.g., diamond and silicon carbide) that require complex and expensive synthesis and patterning processes, CLHPs possess tunable bandgap energies while enjoying the easiness of hydrothermal synthesis in solution.

The proposed research is strategized to integrate numerical design and experimental investigation and leverage the state-of-the-art fabrication and optical characterization facilities at the host site, NIST. Two primary objectives are outlined as (1) Understanding the solution-based synthesis of inorganic WBG perovskites and developing a methodology to realize direct patterning sub-micrometer features; and (2) Employing non-classical states, such as topological states and bound states in the continuum (BIC), in device designs to achieve fabrication-tolerant photonic devices.

The proposed research will engender an innovative direct-patterning methodology and advance the understanding of crystal growth in solution synthesis and capillary force-driven self-assembly, providing invaluable guidelines for other solution-processed inorganic and organic crystals beyond WBG perovskites. The topological device designs, of which properties are not sensitive to local defects, will elegantly compensate for the possible deficiency in the patterning precision and uniformity of the solution process and promise robust device performance.

The integrated photonic platform developed here can serve as a steppingstone toward all-perovskite photonic integrated circuits (PICs) and a unique testbed to investigate the macroscopic quantum phenomena.

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.