Comb-shaped photonic crystal structure for efficient broadband light diffraction and funnelling in solar cells

We present a comb-shaped photonic-crystal (PhC) rods-lattice structure of broadband light diffraction and funnelling for solar cell applications. It is shown that the photonic band of this PhC structure is very dispersive over a broad bandwidth so that light will be efficiently diffracted in the wavelength region of solar radiation. The PhC structure also creates resonance modes leading to further diffraction and funnelling of light so that the light propagates in many pathways in the whole PhC lattice region, which will greatly facilitate light–matter interaction when light-absorbing elements are embedded in the PhC structure. The proposed structure is also valid for photodetection applications.

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► We use dispersive band modes of photonic crystal (PhC) to diffract incoming light.
► The surface of the PhC is carved into comb-shape for broadband light funnelling.
► A model solar cell is designed based on realistic nanofabrication techniques.
► The model consists of the PhC structured TiO2 electrode and colloidal quantum dots.