Polymeric and inorganic semiconductors offer relatively high quantum efficiencies, and are much less expensive and versatile to fabricate than non-amorphous silicon wafers. An optical fiber and cladding can be designed and fabricated to confine light for transport within ultraviolet and near-infrared media, using evanescent waves, and to transmit visible wavelength light for direct lighting.
A new optical fiber was developed that is suitable for solar lighting applications and electrical generation. A key feature is the integration of photovoltaic material for electricity generation. Fiber solar cells surpass both the efficiency and functionality of traditional flat-panel solar cells.
A hybrid solar energy cell device manufactured from this new optical fiber consists of three or four layers of materials, including a combination of n-type nanowires and selected p-type polymers. The fiber has two key features that distinguish it from other fibers. First, the amount of visible light transmitted to the lighting application can be varied by tuning the fiber material. Second, photovoltaic material is integrated into the fiber and can be used to generate electricity from the ultraviolet and infrared portions of the spectrum. If the fiber is tuned to reduce the amount of visible light transmitted to the lighting application, it is also used to generate electricity.
A solar cell manufactured from this new optical fiber has photovoltaic material integrated into the fiber to enable electricity generation from unused light, including non-visible portions of the spectrum, and visible light not transmitted to a lighting application. These new solar cells are based around cylindrical optical fibers, providing two distinct advantages over the flat panels that lead to increased efficiency. The core fiber, used to transmit light, can be adjusted to increase or decrease the amount of available light that is transmitted to the lighting application at any point in real time. This invention can be applied wherever optical concentrators are used to collect and redirect incident light. Wavelengths as large as 780 nm can be used to drive the conversion process. This technology has very low operating costs and environmental impacts (in particular, no greenhouse gas emissions). The fiber uses low-cost polymer materials. It is lightweight and flexible, and can be manufactured using low-cost solution processing techniques.