Abstarct: The peculiar properties of III-V dilute nitrides, namely the substantial reduction of the energy bandgap and the increase of the electron effective mass upon the introduction of a small amount of nitrogen in the III-V matrix which can be grown lattice-matched with GaAs and Ge, make them ideal candidates for solar cell applications. Specifically, the use of 1.0 - 1.25 eV GaInAsN subcells has been proposed as a potential way of enhancing the efficiency of triple and quadruple junction solar cells. However some problems such as doping difficulties and poor minority carrier properties have mitigated the success of these attempts. In this thesis we have tried to study some important parameters in dilute nitride semiconductor baxsed solar cells, including width of the depletion laxyer, minority carrier diffusion length, short circuit current and open circuit voltage affecting the internal quantum efficiency of the device using the well-known theoretical models. Our analysis show in p-n structure solar cells using MBE as the growth method, a low doping level in n-type laxyer and annealing process tend to more efficient samples. We also found in p-i-n structures i-laxyer thickness is crucial in improving the device efficiency. Here in this work we have briefly introduced the presented literature reports in chapter 1 and some important physical properties related to dilute nitride semiconductors, including Ga(In)NAs in chapter 2. In chapters 3 and 4 the basic theories describes the solar cell operation, and related parameters in internal quantum efficiency of such devices are presented, respectively. Finally in chapter 5 we have tried to show the results of our analysis in different reported p-n and p-i-n structures.