Chromaticity manipulation of indoor photovoltaic cells

Organic photovoltaic cells are appealing as indoor illumination harvesters to drive off-grid electronics in the Internet of things. However, a desirable output power usually requires expansive and dark active layers to absorb sufficient incident photons. The deployment of such large-scale dark objects is detrimental to the elaborately designed indoor lighting environment and affects human visual perceptions. Here, we propose a free-contact strategy to adjust the chromaticity of the transmitted indoor light by applying one-dimensional photonic crystals. Combining photonic crystals with various transmittances outside the photovoltaic cells, the spectral power distribution of the transmitted light can be precisely manipulated to realize a broad and consecutive color modulation covering the region from blue to orange. For certain photonic crystals, the chromaticity of propagated light can be recovered close to the light source. This work presents a solution to relieve light-disturbing in the application of organic photovoltaic cells under indoor illuminations.