The role of front and back electrodes in parasitic absorption in thin-film solar cells

Abstract

When it comes to parasitic absorption in thin-film silicon solar cells, most studies focus on one electrode only, most of the time the substrate (in n-i-p configuration) or superstrate (in p-i-n configuration). We investigate here simultaneously the influence of the absorption in both front and back electrodes on the current density of tandem micromorph solar cells in p-i-n configuration. We compare four possible combinations of front and back electrodes with two different doping levels, but identical sheet resistance and identical light-scattering properties. In the infrared part of the spectrum, parasitic absorption in the front or back electrode is shown to have a similar effect on the current generation in the cell, which is confirmed by modeling. By combining highly transparent front and back ZnO electrodes and high-quality silicon layers, a micromorph device with a stabilized efficiency of 11.75% is obtained.

Highly transparent modulated surface textured front electrodes for high‐efficiency multijunction thin‐film silicon solar cells

“…The stability of a‐Si:H can be enhanced by the triode technique, optimized deposition conditions, and thinner absorber layer with the help of efficient light in‐coupling and light trapping . Parasitic absorption losses can be reduced by using highly transparent conductive oxides (TCOs) , more transparent doped silicon oxide layers , and low‐loss back reflectors. However, it is still challenging to design a light‐trapping substrate for multijunction solar cells that can simultaneously provide efficient light trapping and a suitable morphology for the growth of high‐quality absorber layers for each subcell.…”

p-Layer bandgap engineering for high efficiency thin film silicon solar cells

“…[1][2][3][4][5][6][7], but also the base material for thin film silicon based transistors, photodetectors, sensors, and so on [8][9][10]. It has played a critical role not only in thin film silicon based solar cells for building-integrated photovoltaic (BIPV) and flexible lightweight applications [11,12], but also in helping Panasonic to achieve the record efficiency of 25.6% on a commercial sized (143.7 cm²) monocrystallinebased "HIT" solar cell [13].…”