Flexible organic photo-thermogalvanic cell for low power applications

In this paper, we report an organic semiconductor based flexible thermogalvanic cell for conversion of heat and light energy into electric power. This thermogalvanic cell has been fabricated using a eco-friendly, affordable and commercially available organic material known as an orange dye (C₁₇H₁₇N₅O₂), which is soluble in water. The thermogalvanic cell consists of a Carbon/aqueous solution of orange dye/Carbon structure. The cell contains a flexible polymer tube casing, filled with a 5 wt% organic semiconductor orange dye aqueous solution and carbon-electrodes. Gradient of temperature (ΔT) up to 28 K was created by low power electric heater and up to 6 K by illumination. It was found that at ΔT = 8 K, the open-circuit voltage (V _oc ), short-circuit current (I _sc ) and Seebeck coefficient were in the range of −(31–32) mV, −(2.6–2.7) µA and −(3.8–3.9) mV/K, respectively. The thermogalvanic cell holds the promise of potential use in low-power applications (e.g. medical) and temperature gradient measurement.