There is great interest in the numerous technological applications of TiO₂ to photocatalyst, gas sensors, and dye-sensitized solar cells (DSSCs) made from nanostructured TiO₂ electrodes. In organic dyes, Ru-based dyes adsorbed on the electrodes with larger surface areas absorb solar light energy more efficiently. To achieve light-havesting efficiency more effectively, semiconductor quantum dots (QDs) have been the subject of considerable interest as a candidate for light harvesters, which are alternative to organic dyes. The use of semiconductor QDs as photosensitizers has some adbvantages for sensitized solar cells. The crystal growth of semiconductor QDs adsorbed on nanostructured TiO ₂ photoelectrodes is important not only for crystallographic studies but also for improving the photovoltaic efficiency for the solar cells. Only a few general aspects of the growth kinetics of semiconductor QDs were described. In this study, nanoparticle, inverse opal, and nanotube TiO₂ electrodes were prepared, becuase the morphologies of the electrodes are important factors for improving DSSC photovoltaic efficiency. These electrodes are then adsorbed with CdSe QDs as photosensitizers to investigate crystal growth. The average diameters of the CdSe QDs can be estimated from the photoacoustic (PA) spectra. PA spectroscopy is a powereful tool for evaluating the optical absorption of opaque and scattered samples. When the adsorption time increases, the CdSe QD diameter increases and then shows saturation. Normal solution growth plus suppression (negative growth) can be obtained by PA analysis. Both of them depend on the morphology of TiO₂ electrodes and the final solution concentration for the CdSe QD preparation.