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 (10[3]-5[1])(“eh-SAH-key”) to (10[1])exhibit (10[3]-5[1])negative resistance. (10[1])Four (10[1])of these (10[1]-5[1])devices (10[1]-5[2])are arranged in a (-5[1])diamond shape (-5[4])in a (-5[1])bridge (-5[1])rectifier. (10[6]-5[9])These (10[2])devices (10[2]-5[1])have (10[1]-5[1])an (-5[1])exponential (-5[2])I-V (“eye-vee”) relationship (10[1]-5[1])according to the Shockley equation. (10[1]-5[1])Past (10[1]-5[1])the breakdown voltage, these devices (-5[1])can (10[1])conduct in (-5[1])both directions. (10[1])On circuit (10[1]-5[1])diagrams, (10[1])these devices are represented by a triangle touching (10[2])a line. (0[1]-5[1])For 10 points, name (10[1]-5[1])these circuit elements (10[1])that only let current flow in one direction (10[1]-5[1])and come (10[1])in a “light-emitting” type. (10[6])■END■ (10[19]0[4])