[show abstract][hide abstract] ABSTRACT: In this paper, we perform a simulation study on the nanowire-CdS/Cu(In1-x,Gax)Se2, NW-CdS/CIGS, based heterojunction solar cells. In order to calculate the improvement in the efficiency, the light generated current density for the junction was calculated and it is shown that replacing CdS nanowires with bulk CdS, leads up to 17% improving in short circuit current. Band diagram of typical bulk and NW-CdS/CIGS has been calculated and an improvement in band discontinuity in NW-CdS/CIGS observed. Also, light generated current density calculation shows absorption edge shift in CdS nanowires, especially in the range of 400 ~ 480 nm, in comparison with bulk CdS.
4rd Iranian Conference on Photonics Engineering; 01/2012
[show abstract][hide abstract] ABSTRACT: Intermediate band solar cell based on quantum dots suggested as very high efficiency solar cells. But unfortunately, experimental samples show lower efficiency than a cell without quantum dot. In this paper, by solving the current continuity equation with self consistent method, surface recombination rate calculated and effects of surface recombination mechanisms on the efficiency of quantum dot intermediate band solar cell studied and it is shown that charge carrier recombination decreases efficiency of cell. By comparison with calculated photocurrents, it is fund that quantum dots can be act as generation or recombination center. Also, it is shown that only in 10 layers, quantum dots act as generation center and in later layers, quantum dots act as recombination center which leads to decreasing the efficiency. The modeling results in a good agreement with published experimental data.
Conference on Nanostructured Solar Cells (NSSC90); 01/2011