A comparative photophysical study of several new dendrimers consisting of the ethynylphenyl core and carbazole dendrons (1−5) is presented. Dilute solutions of 1−5 show intense blue emission in dichloromethane (λmax = 410−438 nm, ΦF = 0.53−0.91, τF = 2.09−3.91 ns). The solvatochromic and solid-state emission behavior of 1−5 (λmax = 426−443 nm, ΦF = 0.30−0.90) is discussed. The geometry of 5 allows formation of a strong electromeric state, which was not the case with 1, indicating that the ethynylphenyl group can be used to tune dendrimer electroluminescence (EL) properties. An organic light-emitting diode (OLED) consisting of 1 as the emitting layer showed blue emission (CIE: 0.28, 0.20), whereas the EL of 5 (CIE: 0.34, 0.36) was found to be close to ideal white light. White OLEDs consisting of 5 as the emitting layer showed a maximum brightness of 450 cd/m2 and a maximum efficiency of 0.11 cd/A at 11 V.