Project Abstract

Solar electricity is a compelling source of sustainable energy considering the immense harvestable solar resource of approximately 100 terrawatts (TW) vis-à-vis the present global energy consumption rate of about 18 TW. Notwithstanding the enormous progress made in recent years by the solar industry, there still remains the need to reduce the cost of solar electricity in relation to conventional fossil energy sources.

Today silicon solar cells dominate the photovoltaic industry – fundamentally owing to the abundance of silicon in the earth’s crust, its stability as an electronic material, which makes it amenable to many decades of use under continuous solar illumination, and its environmental compatibility. In all fairness, it is quite unlikely that any other material system stands to supplant crystalline silicon dominance in photovoltaics.

However, herein we propose the next step in the evolution of silicon solar cells – low-cost ultraefficient flexible silicon solar cells. We intend to achieve this by integrating state-of-the-art amorphous-crystalline silicon heterojunction technology with ultra-thin (microns-thin) photonic crystal silicon foils, as well as by capitalizing on the latest scientific developments in new photonic crystal architectures and device materials.

Scientific investigations indicate that the proposed technology can achieve world-record silicon solar cell efficiencies on a microns-thin flexible silicon foil. Further, development and integration of the newest junction/heterostructure materials and photonic crystal architectures have the potential of advancing silicon efficiency toward the recognized practical limit of ~29%. Moreover, recent studies also suggest that there are potential device constructs that may open the path toward the Shockley-Queisser limit of ~32%.

This project will pursue several parallel research paths. These include: integrating established amorphous-crystalline silicon technology within flexible silicon photonic crystal foils to develop and demonstrate high-efficient micron-thin silicon solar cells;

integration of novel carrier-selective metal/metal-oxide – silicon heterostructures alongside novel passivation techniques to potentially achieve previously unrealized photovoltaic conversion efficiencies on silicon; development and integration of nanomaterials chemistry to realize roll-to-roll silicon foil photovoltaic technology. The project will also explore and seek discovery of allied novel optoelectronic and photonic devices/applications