Four compounds 4-[3,6-di(carbazol-9-yl)carbazol-9-yl]isoquinoline (TCIQ), 3-[3,6-di(carbazol-9-yl)carbazol-9-yl] pyridine (TCPy), 4-(carbazol-9-yl)isoquinoline (4CIQ), and 3-(carbazol-9-yl) pyridine (CPy) containing pyridyl or isoquinolyl were designed and synthesized to co-deposition with copper iodide (CuI) to form luminescent Cu(I) complex doped film in situ, which could be utilized as the emissive layer in organic light-emitting diodes (OLEDs). It is found that simple tri-layered yellow and white OLEDs can be achieved by co-depositing CuI and TCIQ with tuning ratios. The compound TCIQ serves a dual role as both a ligand for forming the emissive Cu(I) complex and as a host matrix for the formed emitter in yellow OLEDs, and a third role as a blue emitter in white OLEDs.