Joshua B Martin (Fed)

Dr. Martin leads the Transport Property Measurements for Semiconductors and Energy Materials Project to develop critical thermal and electrical transport measurement methods, instrumentation, and reference materials needed to support the development, performance, and reliability of bulk and thin film materials used in semiconductor microelectronics and energy conversion applications. He investigates the properties of materials and interfaces that govern reliability, performance, and thermal transport in advanced microelectronic packages to improve thermal management, which is critical for microprocessors and for wide bandgap semiconductor devices used for energy conversion applications (inverters, AC/DC-DC converters, solid-state lighting, RF, and communication devices).

His research interests also focus on thermoelectric materials, materials that interconvert thermal and electrical energy, with applications that include waste heat recovery in engines for automotive, aerospace, and military applications, and solid-state refrigeration for consumer products and microelectronics. The Seebeck coefficient is an essential indicator of the conversion efficiency and the most widely measured property specific to these materials. However, the intra- and inter-laboratory comparison of Seebeck coefficient measurements has highlighted conflicting data, due to the diversity of instrumentation and the lack of standardized measurement protocols and certified reference materials. To elucidate the influence of these factors in the measurement of the Seebeck coefficient at high temperature and to identify standard testing protocols, Dr. Martin has developed a custom high temperature (300 K – 1200 K) thermoelectric measurement apparatus, which is uniquely capable of in situ comparison of commonly applied probe arrangements and measurement techniques. With the goal of accelerating the development of more efficient thermoelectric materials and devices, he has also completed a comprehensive analysis of 200 years of thermoelectric measurement literature, thereby creating a resource for best measurement practices in the form of a widely accessible review paper. Additionally, he has development a novel finite element analysis approach to simulate and model Seebeck coefficient measurements for the first time, thus enabling the quantification of errors that were previously experimentally inaccessible. Dr. Martin has led the development of two Standard Reference Materials to enable instrument validation and interlaboratory data comparison at both cryogenic temperatures and at high temperatures relevant to thermoelectric waste heat recovery,

Dr. Martin graduated from the University of South Florida with a Ph.D. in Applied Physics in 2008 and then was awarded a NRC Research Associateship at NIST. He is currently leading the project “Measurements, Standards, and Data for Energy Conversion Materials.” We have recently introduced the NIST (National Institute of Standards and Technology) Standard Reference Material® (SRM) 3451 “Low Temperature Seebeck Coefficient Standard: 10 K - 390 K”. This has enabled researchers to calibrate Seebeck coefficient measurement instrumentation and to reliably compare data. Dr. Martin is now developing a complementary high temperature Seebeck coefficient Standard Reference Material (SRM). Dr. Martin is actively involved in the VAMAS Thermoelectric Working Group, leading the effort to identify and disseminate measurement protocols and reference materials.

Opportunities for a NRC Postdoctoral Fellow exist to investigate fundamental material transport properties (Seebeck coefficient, electrical resistivity, heat capacity, thermal conductivity) by developing new measurement techniques and improved measurement instrumentation, to investigate the synthesis of novel materials using both traditional and combinatorial approaches, and to develop advanced manufacturing techniques for semiconductor devices. Opportunities also exist for other energy storage and conversion technologies, including storage devices such as batteries, and transduction technologies that convert energy from a form that is challenging to store into one that is economically favorable or more convenient, including for example, chemical, kinetic, electrostatic, or thermal. More information on this opportunity are available here.

Research Interests

• Develop advanced metrology techniques and instrumentation to characterize thermal and electrical transport properties of materials used in semiconductor microelectronics, thermoelectrics, and other energy conversion materials
• Investigate the structure-property relationships of semiconductors and novel energy conversion materials
• Inorganic materials of interest: semiconductors, wide bandgap semiconductors, functional nanocomposites, open-structured frameworks, and combinatorial films
• Develop new techniques to characterize the thermal properties of materials at high temperature

• 2021 Department of Commerce Silver Medal Award: “For developing critical thermoelectric standards, instrumentation, and metrologies that enable the commercialization of energy conversion materials.”
• 2018 Colleague's Choice Award: For outstanding contributions to the MML Metrology and Accolades Programs, staff professional growth and organizational innovation, and the Combined Federal Campaign
• 2014 Department of Commerce Bronze Medal Award: “For development of Seebeck coefficient metrologies and standards that advance the commercialization of thermoelectric energy conversion materials.”
• Fall 2008 National Research Council Postdoctoral Fellowship at NIST, Gaithersburg, MD