Emission modification of CdSe quantum dots by titanium dioxide visible logpile photonic crystal

Air band modes of three-dimensional photonic crystals (3DPCs) have a higher photonic density of states, potentially enabling greater emission enhancement. However, it is challenging to introduce emitters into the "air" region without significantly disturbing the photonic band structure of the PC. Here, we overcome this difficulty by introducing a low refractive index aerogel matrix containing CdSe quantum dots (625 nm peak emission) into a titanium dioxide logpile PC. We observe that the aerogel infiltration indeed preserves the bandstructure. We measure an emission suppression of ∼0.25 times inside and an enhancement of approximately three times outside the bandgap with only one vertical unit cell. © 2009 American Institute of Physics.