Optical enhancement and losses of pyramid textured thin-film silicon solar cells

Abstract

The optical enhancement and losses of microcrystalline thin-film silicon solar cells with periodic pyramid textures were investigated. Using a finite difference time domain algorithm, the optical wave propagation in the solar cell structure was calculated by rigorously solving the Maxwell’s equations. The influence of the profile dimensions (the period and height of the pyramid) and solar cell thickness on the quantum efficiency and short circuit current were analyzed. Furthermore, the influence of the solar cell thickness on the upper limit of the short circuit current was investigated. The numerically simulated short circuit currents were compared to fundamental light trapping limits based on geometric optics. Finally, optical losses in the solar cell were analyzed. After identifying these key losses, strategies for minimizing the losses can be discussed.

Impurity-doped ZnO Thin Films Prepared by Physical Deposition Methods Appropriate for Transparent Electrode Applications in Thin-film Solar Cells

“…At the present time, AZO and B-doped ZnO (BZO) thin films are in practical use for transparent electrode applications in CuIn 1-X Ga X Se 2 -based thin-film solar cells [9][10][11][12]. In addition, impurity-doped ZnO thin films, such as AZO, GZO and BZO with a textured surface structure as well as a high transmittance in the near-infrared region, have recently attracted much attention for transparent electrode applications in Si-based thin-film solar cells [13][14][15][16][17][18][19][20][21][22][23][24]. It is necessary to form impurity-doped ZnO thin films with a doubly textured surface structure that can effectively scatter the incident visible and near-infrared light [25].…”

Two Approaches for Incoherent Propagation of Light in Rigorous Numerical Simulations

“…Also the first approach of phase matching is more sensible to this discretization error compared to phase eliminating approach. The possible reason for this is the phase eliminating approach is comparing two layers that are close together with the thicknesses (14), and the phase error is more or less the function of the difference. While in the phase matching approach the phase error is related to the whole thickness of incoherent layer.…”

“…Light propagates through the glass before reaching the thin cell. In order to avoid incoherent treatment of glass in rigorous simulations so far, the glass layer was simply omitted in simulations [9][10][11] or the glass, transparent conductive oxide, or Ethylene-vinyl acetate foil in case of substrate configuration, was often taken as incident medium [9,[12][13][14][15]. This, however, can lead to significant inaccuracy and uncertainty of the results since absorption in glass is fully neglected (in case of industrial glasses not always acceptable) and forward and backward reflectance at the front air/glass interface is not considered (in case of light scattering high incident angles of backward going light can result in total reflection at air/glass interface increasing light trapping), not to mention the incidence of light under oblique angles.…”

Emerging Energy Applications of Two-Dimensional Layered Materials

“…Their main drawback is associated with their indirect optical band gap that requires a thick active layer for the solar conversion and thus costly fabrication of large area materials. Furthermore, these cells suffer from many efficiency losses for energy conversion, such as "red losses" (photons with energies below the band gap of the device cannot be absorbed) and "blue losses" (photons with energies above the band gap lose their excess energy as heat) [211][212][213] . TMDCs are a rapidly rising phenomenon in areas like material sciences and nanotechnology.…”