| 摘要 |
PROBLEM TO BE SOLVED: To obtain excellent ohmic contact with a metal electrode, without decreasing the injection efficiency of holes, by forming an electrode on a second layer to which acceptor impurities are added in a concentration range wherein a driving voltage becomes almost minimum. SOLUTION: A P-type layer 61 consists of at least a first layer 62 to which acceptor impurities are added in a concentration range wherein the hole concentration becomes almost maximum, and a second layer 63 to which acceptor impurities are added in a concentration range wherein a driving voltage becomes almost minimum. Electrodes 17, 18 are formed on the second layer 63. Thereby the driving voltage can be decreased, and the injection efficiency of holes to a light emitting layer can be improved. As a result, excellent ohmic contact with metal electrodes can be obtained without deteriorating the injection efficiency of holes. |
