Collaborative Research: Revealing the potential of bismides as efficient midwave infrared optical materials

Nontechnical description Compound semiconductors involve two or more elements. For example, gallium arsenide is a III-V semiconductor that combines elements from Group III and Group V of the periodic table. These materials are prized for their superior electronic and optical properties, which allow for devices that operate at high speed and power, and extreme frequencies. They are widely used in devices such as light-emitting diodes, lasers, sensors, and detectors. Infrared light with wavelengths from 3 to 4 micrometers is the spectral range critical for industrial, biomedical, and security applications. However, fundamental limitations that prevent the use of common compound semiconductors in this range. To address the challenge, this project will develop a new class of compound semiconductor materials. These new materials, called bismides, partially replace more common elements from Group V with bismuth. Preliminary studies show that these bismides emit and absorb light in the desired wavelength range. The team of three investigators with complementary expertise will grow, characterize, and simulate layered bismides for use in novel light emitters and detectors. The research will enable important applications such as eye-safe remote sensing for consumer electronics, light detection and ranging in autonomous vehicles, and highly precise laser-based surgical procedures. Additionally, advanced simulation tools for bismides will be released as open source and the project will also cultivate a skilled semiconductor workforce by training students at all levels. This effort will transform the understanding and development of materials for this vital infrared waveband and enable eye-safe remote sensing for consumer electronics, light detection and ranging for autonomous vehicles, and highly precise laser-based surgical procedures. Technical description This research project will develop bismide-based superlattices on indium-phosphide substrates, designed to emit and detect light in the midwave infrared waveband (3–4 microns). Development of high-performance light sources within this range is a significant challenge owing to fundamental material limitations in current technologies, such as quantum cascade lasers and interband cascade lasers, and the manufacturing complexity of existing gallium-antimonide alternatives, which hinders commercial viability. The approach in this project will overcome these obstacles by adding bismuth to established Type-I and Type-II superlattices on indium-phosphide substrates, extending their operational wavelength into the target wavelength range. Adding small amounts (below 10%) of bismuth will induce a valence-band anticrossing interaction, which dramatically reduces the bandgap. This project will leverage the mature, scalable, and cost-effective indium-phosphide industrial platform, which also offers superior thermal conductivity crucial for high-power device performance. Led by a three-investigator team with complementary expertise in materials growth, characterization, and modeling, this research will address critical knowledge gaps in novel bismide materials and result in a comprehensive knowledgebase for key performance metrics essential for device engineering, including optical dispersion, optical gain, radiative and nonradiative recombination rates, and thermal conductivity. 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. NSF Award ID: 2538696 | Program: 01002627DB NSF RESEARCH & RELATED ACTIVIT | Principal Investigator: Irena Knezevic | Institution: University of Wisconsin-Madison, MADISON, WI | Award Amount: $153,495 View on NSF Award Search: https://www.nsf.gov/awardsearch/show-award/?AWD_ID=2538696 View on Research.gov: https://www.research.gov/awardapi-service/v1/awards/2538696.html