Production of hybrid photodiodes for solar tracking systems and investigation of photovoltaic characteristics

Today, energy needs are mostly supplied from fossil fuels. Harmful emissions from the use of fossil fuels continue to threaten human health and the environment. Therefore, energy saving and the use of renewable energy sources need to be implemented rapidly. Solar energy is a clean and sustainable renewable energy source. Using a photovoltaic (PV) panel, solar energy is converted into electrical energy. The rate of electricity generation from a photovoltaic panel depends on some factors such as solar irradiance, solar cell materials, solar cell surface temperature, etc. When the solar panel receives more sunlight, it generates more power. A steady-state solar panel cannot capture the maximum sunlight at sunlight hour because the position of the sun in the sky changes throughout the day. For this reason, solar tracking systems have been developed to increase the efficiency of the panels by capturing maximum sunlight. These systems track the movement of the sun and ensure that the panels are constantly facing the sun, thus maximizing energy production. Photodiodes are used in solar tracking systems to detect the position of the sun. These semiconductor devices convert the sunlight falling on them into an electrical signal, which changes according to the sun's position in the sky. In the solar tracking system, these signals from the photodiodes are transmitted to the control unit and the system moves the panels towards the sun. In this way, the panels maximize energy production by receiving sunlight in the most efficient way throughout the day. This study was carried out to fabricate a new hybrid photodiode that can be used in solar tracking systems and to investigate the characteristics of this photodiode. For this purpose, Al/p-Si Schottky barrier diodes (SBDs) with zinc oxide (ZnO) interface doped with 5 wt%, 10 wt%, 20 wt% copper phthalocyanine (CuPc) were fabricated using spin coating technique. This work includes the comparative characterization of the current-voltage (I-V) characteristics between diodes configured with different doping ratios of CuPc over a wide voltage range (±5V) and under illumination (10 to 100 mW/cm2). These measurements allowed the calculation of several critical electrical variables such as ideality factor (n), barrier height B), series resistance (Rs), shunt resistance (Rsh), variable density (Nss) and their response under various conditions at various illumination levels (between 10 and 100 mW/cm2) and dark conditions. The diodes were found to have a good rectification ratio (RR) of about 104. The obtained results show that the rectifying properties of the structures can be controlled by CuPc doping. The obtained values indicate that these SBDs can be used as sensitive photodiodes/sensors/detectors.