M91 FastHall measurement controller applications
Fast — ideal for low mobility materials
Hall effect measurement is a key step in characterizing the transport properties of novel electronic materials and devices. It is commonly performed using the traditional DC field method, requiring little more that a stable current source, a voltmeter, a switch and a magnet and is relatively straightforward and reliable for simpler materials with higher mobilities. However, the difficulty increases and accuracy of measurement decreases as material mobilities decrease. This is often the case in promising new semiconductor materials such as photovoltaics, thermoelectrics, and organics.
For the past several years, AC field techniques using advanced lock-in amplifiers and longer measurement windows to extract smaller Hall voltage signals have been used to explore these materials. But extended measurement intervals can also add new forms of error from thermal drift effects. And, of course, results take longer to get, sometimes many hours for very low mobility materials.
The FastHall technique eliminates both of these issues— it accurately measures even extremely low mobility materials in seconds.