ALEXANDRIA, Va., July 7 -- United States Patent no. 12,677,593, issued on July 7, was assigned to Ningbo Lumilan Advanced Materials Co. Ltd. (Ningbo City, China).

"Nitrogen-containing fused heterocyclic compound and applications thereof" was invented by Xiangzhi Li (Ningbo City, China), Ye Cai (Ningbo City, China), Ting-Wei Wei (Ningbo City, China), Huanda Ding (Ningbo City, China) and Zhi-Kuan Chen (Ningbo City, China).

According to the abstract* released by the U.S. Patent & Trademark Office: "The present invention provides a nitrogen-containing fused heterocyclic compound and applications thereof. When the nitrogen-containing fused heterocyclic compound of the present invention is used as a host material of an emitting layer of an orga...