2D modeling of silicon based thin film dual and triple junction solar cells

Abstract

Based on Crosslight APSYS, thin film amorphous Si (a-Si:H)/microcrystalline (μc-Si) dual-junction (DJ) and aSi:H/amorphous SiGe:H (a-SiGe:H)/μc-Si triple-junction (TJ) solar cells are modeled. Basic physical quantities like band diagrams, optical absorption and generation are obtained. Quantum efficiency and I-V curves for individual junctions are presented for current matching analyses. The whole DJ and TJ cell I-V curves are also presented and the results are discussed with respect to the top surface ZnO:Al TCO layer affinity. The interface texture effect is modeled with FDTD (finite difference time domain) module and results for top junction are presented. The modeling results give possible clues to achieve high efficiency for DJ and TJ thin film solar cells.

Modeling study for developing CdZnTe(CdSe)/CIGS tandem solar cells

“…This is because the low affinity reduces the top n-contact metal Schottky barrier height and less amount of bias potential needs to be sacrificed to overcome this Schottky barrier height across the top junction. It is noted the effect of TCO affinity on n-type emitter is just opposite to the effect of TCO affinity on the thin p-type emitter 12,26,27 where high TCO affinity can lead to better cell performance. On the whole, the modeling results demonstrated in this work indicate some clues to achieve high efficiency for the CZT (CdSe)/CIGS tandem cells.…”

“…The simulator also includes many other advanced physical models and offers a flexible simulation environment. A complex non-local inter-band tunneling model 15 is also incorporated for the simulator; this enables an efficient modeling of multijunction solar cells [11][12][13][14] .…”

“…Detailed current matching analyses can be carried out by adjusting the main absorber thickness [11][12][13] . For each selected top junction absorber thickness, a series of simulation is made by varying the bottom junction absorber thickness.…”