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Quantum Photovoltaic Effect:Two Photon Process in Solar Cell 4th International Conference on Renewable Energy Research and Applications Palermo, Italy, 22-25 Nov 2015 Quantum photovoltaic effect:Two photon process in solar cell Dilan ALP Energy Systems of Engineering Department, Sirnak University Sirnak,Turkey [email protected] Abstract— Photoelectric effect using two photon processes is a knowledge: energy problems for the photovoltaic effect in the new research area interest that referrers to science and technology p-n junction which are important in the photovoltaic fields to find out new solar cells. In this review article focuses on conversion, technology of solar cell, construction of examining light-matter interaction in quantum processes which are photovoltaic pannels modules and arrays and control systems. directly or indirectly related to the photoelectric effect and Therefore, a various theoretical PV energy conversion have highlighting recent research results. This model is used as a tool to been constructed for making new generation high efficiency understand and the theoretical limits of the two-color photovoltaic (TPPV) phenomenon and discussed that are useful generation solar cell with physics of photoelectric model. In this model phtovoltaic (PV) materials which are targeting higher efficiency solar the electron energy and momentum relation is well known to cells. This study will focus on the limitations of current photovoltaic be fundamental of electron and light interaction. This cell devices which are high stability, high efficiency and explore photoelectric process is obtained that the Schrodinger equation current research for the advancement of solar cell technology the can be solved by one-electron approximation for periodic possibilities to improve cell technology. crystal field. In this review study will be focus on solution of Keywords-Solar cell, Ligt-matter interaction, Quantum quantum effects on third generation solar cell which employs photovoltaic effect, Two photon process. two photon absorption is strong research area of scientific I. INTRODUCTION relevance. With increasing the need of alternative energy, this demand A. Two-Photon Photovoltaic Effect will be cause the solar research to extend the properties of absorption, charge transfer, and charge separation of cell Two-photon photovoltaic effect (TPPV) is an energy devices and materials. It is the extension of these properties harvesting technique according to two-photon absorption which will create the next generation of highly effective and (TPA). It is conventional to recognize the physicist that more powerful solar energy harvesting devices. Current formed the theory of two photon absorbance in 1931. This was research areas for extending the abilities of cell devices are made in 30 years before the first laser which was constructed infrared absorbing material, quantum dots, microfrabrication, to demonstrate in this theoretical conclusion. In this principle organic thin films which can be use of solar photovoltaic cells occurs when two photons are absorbed at the same time in a The nature of light-electron interaction in nanometer and semiconductor material which is given rise to an electron-hole atomic scales is exemined that absorption of light processes pair and these photon generated carriers are available for which are atom ionization, excitation, emitted charge carrier photovoltaic conversion into electrical power. The photon pairs, photon excess energy dissipation, carrier transport produced electron and hole are then collected for electrical and/or recombination are described in case of exchanged power generation using a homojunction. energy, photon-electron interactions and momentum transfer The two-photon absorption can be considered as the [1]. These quantum processes and the discrete nature of light- quantum, nonlinear optical phenomena of the conventional matter interaction mechanisms are fundamental to (single-photon) photovoltaic effect widely used in solar cells photoelectric effect that ocur at the nanoscale features. that have an energy lower than the semiconductor bandgap. Nowadays the photoelectric effect has been used in a wide As the two-photon absorption is a quantum effect it can be variety of photoelectric and energy conversion device which is represented by the equation: lead to very low cost solar electricity. In this review paper represent that this photoelectric effect can also be receivable P t =X1E t +X2E2 t +X3E3 t +…+XnEn t (1) advantage of in wavelength converters [2,3]. II. QUANTUM PHOTOVOLTAIC ENERGY CONVERSION The Equation (1) present the anharmonical model which describes the displacement of the charges of an system by the During the last five decades, the high demand for clean interaction of electric field. P(t) represents the polarizability of electricity has led to a great diversity of solar energy material model as a electrical field strength. E(t) represents conversion concepts that are involved a wide range of ICRERA 2015 4th International Conference on Renewable Energy Research and Applications Palermo, Italy, 22-25 Nov 2015 electric field strength and terms and Xn are the nth order efficiency limit of %31 [13] and 63% efficiency limit for susceptibility coefficient. This equation is non-linear two- operation in IB mode [14]. photon absorption which would be incomplete without the mathematical representation of the wave interaction with non- CB linear material because the nonlinear absorption effect is defined as a quantum event. The wave equation in nonlinear is IB EL given as: 2 2 2 2 n ∂ E 4π ∂ P ∇ - 2 2 = 2 (2) c ∂t c ∂t EG EH Where n is the refractive index and c is the speed of light in VB vacuum. The two-photon absorption process is described as third order polarizbility of material given by the equation [4]: 3 3 3 P t =X E t (3) Fig. 1. Structure of an intermediate band (IB) material [11]. In Equation (3) is polarizblity of the materials which was the first discovered in silicon has been specifically investigated in B. Quantum Dot Solar Cell Raman amplifiers. This is particularly for nonlinear optical devices in which the high intensity light required for nonlinear Quantum dots are ultra-small bits of semiconductor new interactions usual TPA inevitable [5,6]. And later observed materials that can be designed with nearly atomic scale by the experimentally in gallium arsenide [7] then, achieving energy- contemporary methods. This particles have been make smaller efficient electronic-photonic integrated circuits [8]. This new below the dimension of the Bohr radius or comparable to their research area related to light-electron interaction within third deBroglie wavelenght. As the energy of the atom can exist generation solar cell will be represented. The next quantum within them become finite energy of the electron which are effect is included in nanostructure PV device operation is tunable by changing their size and defines the bandgap [15]; electron tunneling through energy barriers. These model is the greater the difference in energy between the highest called Quantum Dot (QD) solar cell that will lead to ultrahigh valence band and the lowest conduction band becomes, so efficiencies photocurrent [9,10]. All the above high-efficiency more energy is needed to excite the dot, and the crystal returns view have in common that they rely on quantum effects in low to its ground state. Also such tuning, the main advantage with dimensional semiconductor nanostructures. This model use of quantum dots is the capability to tune the size of the dots for modern solid state theory is indicated, solid state laser and many applications which is the larger quantum dots have a quantum transport theory, which are both well developed and greater spectrum shift towards red compared to smaller dots. can now provide the required theoretical concepts and tools On the other hand, smaller particles are allowed to take which are predicted to bring a innovation the major global advantage of a quantum effect[16]. concerns of health and medicine, energy, and technology In the bulk semiconductor material can have a range of through imaging and sensing, photodynamic therapy, optical energies that can be disclosed as continuous. (Fig. 2.) There is limiting, non-linear data storage and absorption abilities of the a specific forbidden range of energies called bandgap, the materials [11]. energy levels below bandgap is valence band and also very few of them above the bandgap are called conduction band. III. HIGH EFFICIENCY SOLAR CELL Nanoparticles Bulk Model λ: Wave length λ: Wave length The third generation device includes nono semiconductor technologies, quantum dot, multi-junction cells, intermediate band solar cell, hot carrier cells, photon Radiation shift between up and down conversion technologies and thermal the two edges of visible technologies, such as thermophotonics which are known spectra technology defined as being third generation solar cell. Energy Level A. Intermediate Band Solar Cell Energy Level In Intermediate Band (IB) solar cell, two-photon absorption process is produce a optical transition between ΔEnano> ΔEbulk valance and conduction bands through the laying within the ΔEbulk bandgap. To capture and use photons which are based on IB ΔEnano materials are characterized by existence of IB located between the conventional semiconductor conduction band (CB) and valance band (VB) (Fig. 1.) [12]. The detailed theory of ideal p-n junction solar cell allow of evaluation of conversion Fig. 2. Quantum confinement is increase of energy difference between energy
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