Standardizing Performance Measurement of Dye-Sensitized Solar Cells for Indoor Light Harvesting

During the last five years the demand of indoor photovoltaic (IPV) technology is growing rapidly for the Internet of Things. Until now, there is no standardized measurement methodology for IPV devices. So, it is very hard to estimate device efficiency accurately in indoor illuminating condition. This is one of the main obstacles for the commercialization of IPV devices. A standardized universal measurement methodology is highly needed. Therefore in this study, a series of N719 dye based dye-sensitized photovoltaic (PV) cells have been fabricated by varying the working electrode thickness. Then, a low irradiance measurement system has been configured to develop an ideal indoor environment with diffused light by adjusting the distance (1.4 m) between the test cell and light source. Furthermore, the inner wall of the measurement system has been covered by white paper. PV cells are tested under the illumination of three different light sources such as cold cathode fluorescent lamp (CCFL), cool white LED (LED 5600 K), and warm white LED (LED 3200 K)), at the same irradiance power intensity (
$150~\mu \text{W}$
/cm
²
) and luminance (500 Lux) values, to standardize the measurement methodology for PV cells in indoor environment. This study shows that, the response of a PV cell to different light sources can be realized more accurately, if the PV cell is tested under the illumination of different light sources at a fixed irradiance power intensity value instead of a fixed luminance value.