Semi-closed tubular light-trapping geometry dye sensitized solar cells with stable efficiency in wide light intensity range

Abstract

A semi-closed tubular light-trapping geometry is developed for dye sensitized solar cell to stabilize its power conversion efficiency (PCE) in wide light intensity range. The tubular cell consists of a dye-sensitized porous TiO2 coated and semi-closed glass tube as photoanode, an opaque platinum metal foil wrapped on the outside of photoanode as counter electrode, and electrolyte filling in their interlayer. The open end of photoanode serves as the only light entrance. The experiment, calculation and optical studies demonstrated that the tubular geometry is beneficial to light trapping and absorption, charge transport and heat dissipation, in comparison to a planar counterpart. The PCE of tubular cell can remain about 85% of its original value even if the irradiated light intensity increases from 1 to 5 Sun, in contrast, that of planar counterpart decreases to about 60% of its original value. This feature makes the tubular cell has potential as an effective light collector in low-cost condenser solar cell system.