Title:	Whisperonic Solar Cells
Author(s):	C. Sudakar, T.K. Das, P. Ilaiyaraja
Keywords:	Scattering, Solar Cells, Whispering gallery mode, WSC
Topic:	New Materials and Concepts for Photovoltaic Devices
Subtopic:	New Materials and Concepts for Cells and Modules
Event:	35th European Photovoltaic Solar Energy Conference and Exhibition
Session:	1AO.3.5
Pages:	55 - 57
ISBN:	3-936338-50-7
Paper DOI:	10.4229/35thEUPVSEC20182018-1AO.3.5
Price:	0,00 EUR
Document(s):	paper

Abstract/Summary:

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Sensitized solar cells (SSC), including DSSC and QDSSC, are third generation solar cells, which aim to achieve low cost, highly efficient solar light to electricity conversion devices. The challenge that prevails till today is to find approaches to achieve high efficiency. Of several important factors that limit the efficiency in these SSC, including poor connectivity of the TiO2 nanoparticles, charge separation and transport in the photoanode layer, inefficient light absorption by the dye/quantum dot, non-directional transport of charge carriers with significant recombination, and inefficient loading of the sensitizer on the photoanode, the non-optimal utilization of the light entering the devices is the most important one. A large fraction of the light that enters the solar cell gets lost or do not get converted into excitons. Here we propose a new type of solar cell called “whisperonic solar cells (WSC)”. To make efficient use of the light entering the device, WSC, a modified version of Grätzel solar cell, uses mesoporous microspheres exhibiting whispering gallery modes as the photoanode. Enhanced power conversion efficiency of devices is achieved by the efficient scattering of light by way of intense optical whispering gallery modes that eventually gets absorbed by the sensitizer in an efficient way. Mesoporous micron-sized spheres in addition to exhibiting large Mie scattering (whispering gallery modes) can be used to load large fraction of quantum dot sensitizer. Further, using composite photoanode (mesoporous microspherical TiO2 in combination with the nanocrystalline TiO2) better connectivity among the particles leading to directional transport is achieved. The recombination of charge carriers is suppressed largely with these composite photoanodes. All these characteristics of the photoanode have been tested in the dye, quantum dot and thin film sensitized solar cells. Using CdSe and CuInS2 QDs, and CuInS2 thin film in the WSC devices we show significant enhancement in the power conversion efficiencies.