New research done by IBM made a breakthrough in answering a mystery that has puzzled physicists for 140 years ago. It promises to leading new generation with semiconductor materials and devices that use them.
The invention of semiconductors was helpful in bringing us in the era of digital. We can find these electricity carrying substances in our smartphone and computer. An improvement in this field could have major consequences for future gadgetry.
The American physicist Edward Hall discovered the Hall effect in 1879 shows measuring of electricity in a conductor flow. He found that we can measure the amount of deflection because a magnetic field deflects the movement of electronic charges in a conductor. As a result, number will describe the voltage perpendicular (or transverse) to the flow of charge.
Modern researchers documented that making Hall effect measurements using light in so called photo Hall experiments that generate multiple carriers (or electron-hole pairs) in superconductors. Unfortunately, while the Hall voltage provides crucial information about these charge carriers in a semiconductor by limited to the properties of the dominant (or majority) charge carrier.
Finding out the information about both the majority and minority charge carriers, which impact changes in conductivity, would be key to advancing applications utilizing light, including optoelectronic devices like solar cells, LEDs, and lasers as well as artificial intelligence tech.
Now a new formula and technique for getting both the majority and minority carrier information was developed by researchers from KAIST (Korea Advanced Institute of Science and Technology), KRICT (Korea Research Institute of Chemical Technology), Duke University, and IBM.
The method for measurement named as Carrier Resolved Photo Hall (CRPH). This method instantaneously extracts information about the majority and minority carriers like density and mobility, carrier lifetimes and lengths of diffusion. In fact, compared to the three parameters of measurement traditionally derived by engaging the Hall effect, the novel technique can get up to seven parameters of information.
The approach also takes advantage of a tool developed by IBM called the parallel dipole line (PDL) trap, which generates an oscillating magnetic field. It works as an ideal system for photo-Hall experiments because of the large amount of space it allocates for sample illumination.