A theoretical investigation of quantum confinement effects in heterojunction silicon solar cells

The effect of quantum confinement potential on the performance of a silicon-based heterojunction solar cell with an intrinsic thin-layer of a-Si:H is studied using numerical simulations. The presence of defects at c-Si/a-Si:H interface is studied quantitatively and, an analytical solution is investigated to interpret experimental results. Moreover, the impact of defect density at c-Si/a-Si:H interface on the solar cell operation is explained. By the use of a theoretical model, the effect of intrinsic amorphous layer thickness, and interface defect density on quasi-Fermi level are studied and the mechanisms of open circuit voltage (V oc ) variations, are interpreted successfully. It is shown that the best performance of heterojunction silicon solar cell with a single passivation layer is obtained when the thickness of (i)a-Si:H is 3–9 nm and heterojunction interface defect density is lower than 1010 cm−2 eV−1.