The characteristics of the photovoltaic performance
of the highest-efficiency nanotube CdS-CdTe solar cell
were studied under dark and 1-sun irradiation using a
solar simulator, which was calibrated using a standard
light meter. Figure 5(a) shows the current density–
voltage (J–V) characteristics of our “best” nanotube
solar cell under dark and standard 1-sun illumination
conditions. The extracted J–V data for the CdS-CdTe
nanotube solar cells yields a short current density (Jsc)
of 25.5 mA/cm2, an open-circuit voltage (Voc) of 750 mV,
and a fill factor of 55.9%, resulting in an overall power
conversion efficiency (PCE) of 10.7%.