Controllable synthesis of multicolor Alq₃:DCM single-crystalline microrods for optical waveguides

It has been demonstrated that organic semiconductor micro-/nanocrystals with multicolor emission/waveguide characterizations would be widely utilized as ideal building blocks for the next generation of miniaturized optical, electronic and logic operation devices. However, rational synthesis of one dimensional micro-/nanocrystals with multicolor emission and optical waveguide performances are highly desirable and still remain a challenge. Here, the DCM doped Alq₃ single-crystalline microrods are fabricated via a facile solution-exchange method. It is found that a redshift in light-emission frequency is extremely sensitive to the doping concentration of 4-(dicyano-methylene)-2-methyl-6-(4-dimethylamino-styryl)-4Hpyran (DCM) guest molecule. The green emission at 527 nm of Alq₃ is the main emitting peak when doping concentration of DCM in Alq₃:DCM is less than 150:1. Then, when the doping concentration of DCM in Alq₃:DCM is larger than 100:2 such as 100:10, the red emission at 635 nm becomes the dominant emitting peak, the redshift amounts can reach to roughly 108 nm. In addition, the DCM-doped Alq₃ microrods exhibit a lower optical loss of 0.019 dB/μm as a multicolored waveguide material. Therefore, it is demonstrated that the DCM-doped organic micro/nano crystals can be utilized as a promising building block for various optoelectronic components.