Tunable photoluminescence of porous silicon by liquid crystal infiltration
Qing-lan Maa, Rui Xiong a, Yuan Ming Huang b,n
a Department of Physics, Wuhan University, Wuhan, Hubei 430072, China
b School of Mathematics and Physics, Changzhou University, Jiangsu 213164, China
a b s t r a c t
The photoluminescence (PL) of porous silicon films has been investigated as a function of the amount of liquid crystal molecules that are infiltrated into the constricted geometry of the porous silicon films.A typical nematic liquid crystal 4-pentyl-40-cyanobiphenyl was employed in our experiment as the filler to modify the PL of porous silicon. It is found that the originally red PL of porous silicon films can be tuned to blue by simply adjusting the amount of liquid crystal molecules in the microchannels of the porous films. The chromaticity coordinates are calculated for the recorded PL spectra. The mechanismof the tunable PL is discussed. Our results have demonstrated that the luminescent properties of porous silicon films can be efficiently tuned by liquid crystal infiltration.