The photovoltaic and photodiode properties of Au/Carmine/n-Si/Ag diode

© 2023 Elsevier LtdIn this study, carmine films were deposited on glass slides and n-Si substrates using a spin coater. The scanning electron microscope (SEM) and absorbance analyses of the deposited carmine film on glass were performed. Twenty-four (24) Au/Carmine/n-Si/Ag dots were identically fabricated, and their current–voltage (I–V) characteristics were taken at room temperature, both in the dark and under daylight. It was seen that all diodes exhibited a rectifying behavior. The ideality factor (n, IF), barrier height (Φb, BH), rectification ratio (RR), and series resistance (Rs) of each dot were determined using the thermionic emission (TE) theory and modified Norde's functions, respectively. Although the dots were prepared on the same substrate, there was a difference from one dot to the next. The n and Φb values of the 24 dots were found in the range of 1.52–2.72 and 0.76–0.85 eV in the dark, respectively. Furthermore, a high current rectification ratio of 104 was achieved for the 11 dots in the dark. The photovoltaic and photodiode properties of one (labeled as D18) of the Au/Carmine/n-Si/Ag dots under the different light intensities varied from 30 to 100 mW/cm2 at room temperature, and its capacitance–voltage (C–V) characteristics were investigated only in the dark. The D18 dot exhibited typical photodiode behavior with a fill factor (FF) value of 36.2 % and an experimental efficiency (ŋ) of 2.45 % under 30 mW/cm2 light intensity, respectively. It also has a high ON/OFF current (Ion/Ioff) ratio of 7.45x103. Because the maximum current value of the Au/Carmine/n-Si/Ag photodiode has not changed, it exhibits good stability for 12 on/off cycles. According to these experimental findings, the high-performing Au/Carmine/n-Si/Ag diode displays good photodiode behavior, and photodiodes based on the carmine thin film can be used to develop future optoelectronic devices.