A class of these circuit elements called transferred electron devices are used in oscillators to produce microwaves. Quantum tunneling allows a class of these (10[1])devices named for Leo Esaki (“eh-SAH-key”) to exhibit negative resistance. Four of these devices (-5[1])are arranged in a diamond shape (-5[1])in a bridge rectifier. (10[1]-5[2])These (10[1])devices have an exponential (-5[1])I-V (“eye-vee”) relationship according to the Shockley equation. Past the breakdown voltage, these devices can conduct in both directions. (10[1])On circuit diagrams, these devices are represented by a triangle touching a line. (-5[1])For 10 points, name these circuit elements that only let current flow in one direction and come in a “light-emitting” type. (10[2])■END■ (10[4])