Mesoporous
TiO2 nanoparticles are excellent photoanodes for sensitized
solar cells (SSC). However, a significant loss in the photoconversion
efficiency (PCE) occurs due to the inefficient light absorption. Large
Mie scattering from mesoporous micron-sized spheres could be used
to enhance the absorption and hence the PCE. Here, we show that a
composite comprising a TiO2 mesoporous microsphere with
smooth surface (SμS-TiO2) exhibiting whispering gallery
modes (WGM) and a commercial TiO2 mesoporous nanoparticle
(Degussa P25) with an optimum ratio (80:20 wt %) shows significant
enhancement in PCE of DSSC and QDSSC devices. SμS-TiO2 exhibits strong WGM as evidenced from the photoluminescence studies
carried out using a laser with an excitation wavelength λexc = 325 nm. These microspheres sensitized with N719 dye or
CdSe/CuInS2 QDs are shown to exhibit emission characteristics
strongly coupled to WGM resulting in an enhanced PCE in SSC. Increases
in PCE of ∼24% in DSSC devices and 80–95% in QDSSC devices
of 0.25 cm2 area are demonstrated. Thus, TiO2 composite exhibiting WGM can be used as a generic photoanode to
achieve maximum PCE for Grätzel type sensitized solar cells.
This study suggests special class of solar cells called “whisperonic
solar cells”.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.