The cells were illuminated using a solar simulator at AM1.5G
(Newport AAA solar simulator at 100 mW/cm2). The intensity of
solar cell was calibrated with standard Si-reference cell. External
quantum efficiency (EQE) was measured as the function of wavelength from 300 nm to 1100 nm using Bentham PVE300 unit with
a TMc300 monochromator based IPCE with the Xenon arc lamp. A
calibrated type DH Si photodetector used as a reference. Scanning
electron microscope image was took by Carl zeiss EVO LS 15
scanning electron microscope. Electrochemical impedance spectroscopic (EIS) measurements were performed under dark and
light conditions by using Zahner Zannium universal electrochemical work station equipped with a frequency response analyzer (Thalas) in the frequency range from 0.1 Hz to 1 MHz and
10 mV amplitude ac signal. Absorbance spectra were recorded by
using Shimadzu 2450 UV–Visible spectrometer. Open circuit voltage decay measurement was performed with Tektronix 3032B
digital phosphor oscilloscope. Once the stable voltage reached
under illumination, shutter was turn off and voltage decay was
recorded.