Patent ID: 7755275
Filing Date: 2010-07-13
Classification: H01L

Abstract:
1. A cascaded light emitting device, comprising: a base electrode formed of a first electrode material, the base electrode including unevenly sized electrode portions having a longer portion and a shorter portion; a top electrode formed of a second electrode material, the top electrode including unevenly sized electrode portions having a longer portion and a shorter portion, wherein the shorter portion of the top electrode opposes a part of the longer portion of the base electrode, and the longer portion of the top electrode opposes a part of the longer portion of the base electrode and the shorter portion of the base electrode; a plurality of electroluminescent layers coupled between the base electrode and the top electrode, each of the electroluminescent layers including a mixed conductor that luminesces with a peak wavelength, wherein each electroluminescent layer is a single layer structure; and at least one middle electrode layer formed of a middle electrode material, wherein the at least one middle electrode layer is coupled between two juxtaposed electroluminescent layers of the plurality of electroluminescent layers, wherein the at least one electrode layer includes three middle electrode portions that are sized such that three rows of the middle electrode portions are formed, the three rows including first and second side rows and a center row, the first side row corresponding horizontally to the shorter portion of the top electrode and the longer portion of the base electrode, and the center row corresponding horizontally to the longer portion of the top electrode and the longer portion of the base electrode, and the second side row corresponds horizontally to the longer portion of the top electrode, such that, in operation, current flows in a serpentine pattern from the shorter portion of the top electrode to the longer portion of the base electrode along the first side row, and from the longer portion of the base electrode to the longer portion of the top electrode along the center row, and from the longer portion of the top electrode to the shorter portion of the base electrode along the second side row.