The purpose of this study is to determine the optimum location for intermediate band in the middle of band gap of an ideal solar cell for maximum performance. By changing the location of the intermediate band, output current and therefore performance can be changed. Choosing the best location in terms of solar cell energy gap and how to change the performance by means of the location of intermediate band has the important role in the energy band gap engineering. This matter in the known methods of the intermediate bands realization such as quantum well and quantum dots can be used for selecting the type of semiconductor in quantum well or quantum dot and also for selecting dimension of quantum dot or quantum well. Conclusion of this paper is by increasing energy gap, the optimal location of intermediate band for cells with one intermediate band, will be closer to the middle of the energy gap. تفاصيل المقالة

In this paper the idea of an intermediate band solar cell which increases the efficiency of solar cells is considered. By using quantum dots the idea of intermediate band solar cell can be achieved in acceptable level. Actual results of using quantum dots have been led to decrease efficiency of solar cell. The effect of absorption coefficients on upper limit of efficiency in special type of solar cell is focus in this paper the main factors which have most impact on the upper limit of efficiency of our position of intermediate bands and consequently the structure of quantum dots. Furthermore, the changes in cell characteristics, quantum dots type, quantum dots structure, and even polarization of the incident light can change the upper limit of efficiency. Changes distances layers of quantum dots create different results for different polarization of light for upper limit of efficiency. Using the results of this research can be a way to new research in the field of solar cells with quantum dots and the optimum use of solar cells will be useful. تفاصيل المقالة