FABRICATION AND CHARACTERIZATION OF HIGH-QUALITY ORGANIC MULTIPLE-QUANTUM-WELL STRUCTURES

High quality organic multiple quantum well (MQW) structures consisting of alternating layers of tris(8-hydroxyquinoline) aluminum (Alq(3)) a nd iphenylyl)-5(4-tert-butyl-phenyl)-1,3,4-oxadiazole (PBD) have been prepared by a multisource-type high-vacuum organic molecular beam depo sition (OMBD) system which we have designed specially to improve the l arge-area uniformity and abrupt interfaces. Small angle X-ray diffract ion, optical absorption and photoluminescence measurement results indi cate that the MQW structures have a very uniform layered structure thr oughout the entire stack, and interfacial roughness is smaller than 1. 0 nm. Exciton energy shift to a high energy region with decreasing Alq 3 layer thickness has been observed. (C) 1998 Elsevier Science S.A. Al l rights reserved.