Task: Text Categorization
Input (English): One variety of this type of device works because quantum mechanical tunneling causes an increase in voltage to result in a decrease in current. That variety is noteworthy for the small size of its key component, which is often about one hundred angstroms wide, and is known as the tunnel variety. Another type of this device works by being reversed biased, thus keeping the voltage close to a namesake voltage. That variety often used as a shunt voltage regulator is named after an American physicist who also has a namesake pinning. One common type of these devices uses materials with a direct band gap, and like all of these devices, consists of a semiconducting chip doped with impurities to create a P-N junction. Including Zener varieties, for 10 points, name this device which conducts electric current in one direction, the most famous type of which emits light.
Output (English): Science