Kansas State University will acquire a Hall effect measurement system for characterizing the electron transport properties of novel semiconductors. This is a highly sensitive system capable of measurements over a wide resistance range (0.05 mW to 200 GW), with a maximum voltage of 95 V, and minimum and maximum currents of 500 fA and 100 mA respectively. The system includes a variable gap electromagnet with a maximum field strength of 1.04 T. Computer controlled variations of the magnetic field and applied voltage makes it possible to distinguish the electrical properties of individual layers in multilayer samples. Many semiconductors with a wide range of applications will be studied including B12As2 -a candidate for radiation detection and direct nuclear to electrical energy conversion devices, heavily doped aluminum nitride for deep ultraviolet LEDs and laser diodes, HgI2 and CdZnTe for solid state radiation sensors, and other semiconductors of emerging importance. The state-of-the-art capabilities and ease of use of this system will help to promote collaborations between students and faculty in different disciplines on campus and between universities. Hall effect measurements will be incorporated into demonstrations and experiments in undergraduate engineering courses to enhance student learning of mobility and charge carrier concentrations, as measured by this widely employed technique.
Lay Abstract
Hall effect measurements are the most common method to determine the electrical properties of a semiconductor, such as electron speed and concentration. These properties must be known to design and fabricate all types of electronic devices such as light emitting diodes (LEDs), laser diodes, and sensors to detect light (from ultraviolet to infrared) and nuclear radiation. Such devices are found in traffic lights, automobiles, laser printers, compact disc players, and environmental and safety monitors, just to cite a few examples. The new Hall effect measurement system will enhance a growing cross-disciplinary program at Kansas State University in sensor development. Characterization provided by this system will lead to better materials and new, more efficient and sensitive sensors. The system will also help with student education; new experiments using this system will be incorporated into the laboratories of undergraduate engineering students, to help them to better understand the electrical properties of materials. This system will be displayed at educational outreach activities such as the university open house and summer institutes for high school students, to spark interest in science by the general public and to encourage students to consider careers in technology.
