Sharif Digital Repository

Schizophrenia is a devastating disorder that steals the opportunity of having a normal life from the sufferers. Drugs used in treating this disorder usually target psychotic symptoms and do not affect negative symptoms effectively. One of the deficits falling into this category is the impaired reversal learning. These patients usually learn the rules but do not renounce them after the contingencies of reward have been reversed. To investigate the reasons of this impairment, first a hypothesis of how different parts of the brain communicate during reversal learning is proposed using the physiological evidence. Then considering the known relation between the actor-critic model of the... 

In this research, we focus on study and fabrication of organic inorganic solar cells. We use and optimize various methods such as one-step spin-coating, two-step sequential deposition and vapor-assisted solution process (VASP), to prepare high quality perovskite films. One-step deposition is simplest method for deposition of perovskite films. Although perovskite deposition by this method is very simple, the control of uniformity and surface film morphology is difficult. Chlorine inclusion, optimization of annealing conditions, and a sequential solution-based deposition method have been demonstrated to increase film coverage and uniformity. Hence, we use sequential deposition method for... 

Quantum entanglement and superposition are wonderful and mysterious phenomena of quantum mechanics. By means of quantum entanglement, two or more systems become partner in state of each other . As a result, measurements on each of these systems affect the status of other systems. Quantum superposition allows a system inhabits several of its possible quantum states simultaneously. These two features are applicable in many technologies in present age. Photons, as an quantum unit of light, are appropriate candidate for utilization these properties. Because they are robust to decoherence and for their preparation exist various methods. Hence, we interested to generation of quantum states of... 

The use of renewable energy sources has received much attention due to the increasing need for energy, limited energy resources and the pollution of fossil fuels. Among all types of solar energy conversion technology, photovoltaics has the highest technical potential and Iran’s geographical location is very suitable for benefiting from this energy. So, in this thesis, the fabrication and characterization of nanostructured solar cells based on organic-inorganic perovskites have been investigated. Many research goups have tried to increase the efficiency of perovskite solar cells. The efficiency of this kind of solar cells depends mainly on the light-absorbing layer (perovskite) and its... 

Perovskite solar cells (PSCs) have emerged as a promising photovoltaic technology due to their high power conversion efficiency, ease of fabrication, relatively low production cost, and compatibility with various scalable deposition techniques. Nevertheless, several critical challenges including sensitivity to moisture and ambient oxygen, long-term instability, and the widespread use of toxic anti-solvents during film fabrication still hinder the large-scale commercialization of PSCs. Achieving perovskite layers with high crystalline quality, uniform and stable morphology under ambient conditions, and without employing harmful chemicals is a key bottleneck for industrial development. The... 

Solar cells, as a part of photovoltaics (PV) industry, have a significant share in the renewable energy market. Perovskite solar cells (PSCs) and thin film solar cells (TFSCs) achieved 23% and 22% power conversion efficiencies (PCEs) respectively. However, the PV industry still faces challenges like “high manufacturing costs” and “stability”. Among the strategies to overcome these challenges are substitution of the costly materials with cheaper, more abundant ingredients along with utilizing inexpensive deposition methods like printing rather than vacuum-based methods such as evaporation and sputtering. Carbon materials attract more attention in the solar cell research community for their... 

Perovskite solar cells (PSCs) have emerged as a leading thin-film photovoltaic technology owing to their outstanding optoelectronic properties, low fabrication cost, and compatibility with flexible substrates. However, the intrinsic instability of methylammonium (MA)–containing compositions remains a major barrier to commercialization; therefore, developing stable MA-free inks is essential for achieving efficient and durable devices. This dissertation presents an integrated strategy for improving the performance and stability of formamidinium-based, MA-free PSCs with carbon electrodes, built on three pillars: ink-formulation engineering, crystallization control, and interfacial modification....