学科进展系列报告

Low Dimensional Metal Halide Perovskites and Hybrids

Biwu Ma

Department of Chemistry and Biochemistry, Florida State University

ABSTRACT

Organic-inorganic metal halide hybrids are an important class of crystalline materials with exceptional structural and property tunability. Recently metal halide perovskites with ABX₃ structure have been extensively investigated as new generation semiconductors for various optoelectronic devices, including photovoltaic cells (PVs), light emitting diodes (LEDs), photodetectors, and lasers, for their excellent optical and electronic properties. By controlling the morphological dimensionality, low dimensional metal halide perovskites, including 2D nanoplatelets, 1D nanowires, and 0D quantum dots, have been developed to exhibit distinct properties from their bulk counterparts, due to quantum size effects. Besides ABX₃ perovskites, organic-inorganic metal halide hybrids, containing the same fundamental building block of metal halide octahedra (BX₆), can be assembled to possess other types of crystallographic structures. Using appropriate organic and inorganic components, low dimensional organic metal halide hybrids with 2D, quasi-2D, corrugated-2D, 1D, and 0D structures at the molecular level have been developed and studied. Due to the strong quantum confinement and site isolation, these low dimensional metal halide hybrids at the molecular level exhibit remarkable and unique properties that are significantly different from those of ABX₃ perovskites. For instance, broadband white emissions have been achieved in single crystalline bulk assemblies of 1D metal halide nanowires and nanotubes; and near-unity photoluminescence quantum efficiency has been realized for a number of 0D organic metal halide hybrids. In this talk, I will discuss our recent efforts on the development and study of  low dimensional metal halide perovskites and hybrids, from synthetic control to device integration.

BIOGRAPHY

Dr. Biwu Ma is currently an associate professor in the Department of Chemistry and Biochemistry at the Florida State University (FSU). He is also a faculty affiliated with the Materials Science and Engineering Program. He received his Ph.D. in Materials Science from University of Southern California in 2006 with research work in OLEDs under the guidance of Prof. Mark Thompson. He then performed postdoctoral research in Plastic Electronics with Prof. Jean Fréchet at the UC Berkeley and Lawrence Berkeley National Laboratory (LBNL) for two and a half years from 2006 to 2008. He began his independent career in June 2008 as a Staff Scientist at the Molecular Foundry at LBNL, and joined FSU in August 2013.

Dr. Ma’s research has been focusing on the development of new functional materials for applications in a wide range of areas from energy to environmental and information technologies. Of particular interest are new generation electronic and energy devices, including light emitting devices for full color displays and solid-state lighting, solar energy conversion devices, transistors, and sensors. The research activities involve materials synthesis, characterization, and processing, device fabrication and testing, and theoretical computation and simulation. Material engineering at the molecular level is emphasized to deliver a variety of materials, including organics, organometallics, polymers, and organic-inorganic hybrid materials with well-controlled properties and functionalities. Fundamental studies of the structure-property-processing-performance relationships allow for the further development of materials and devices with desired properties and performance in a rational manner, which will eventually deliver new generation technologies for real applications. Dr. Ma has authored and co-authored about 80 peer-reviewed publications in high impact journals, with a total of citations of more than 7200 and an H-index of 40 as of today.