Glass-Encapsulated Light Harvesters: More Efficient Dye-Sensitized Solar Cells by Deposition of Self-Aligned, Conformal, and Self-Limited Silica Layers

Abstract

A major loss mechanism in dye-sensitized solar cells (DSCs) is recombination at the \(TiO_2\)/electrolyte interface. Here we report a method to reduce greatly this loss mechanism. We deposit insulating and transparent silica \((SiO_2)\) onto the open areas of a nanoparticulate \(TiO_2\) surface while avoiding any deposition of \(SiO_2\) over or under the organic dye molecules. The \(SiO_2\) coating covers the highly convoluted surface of the \(TiO_2\) conformally and with a uniform thickness throughout the thousands of layers of nanoparticles. DSCs incorporating these selective and self-aligned \(SiO_2\) layers achieved a 36% increase in relative efficiency versus control uncoated cells.