International audienc

No abstract

The integration of two-dimensional (2D) periodic nanopattern defined by nanoimprint lithography and dry etching into aluminum induced crystallization (AIC) based polycrystalline silicon (Poly-Si) thin film solar cells is investigated experimentally. Compared to the unpatterned cell an increase of 6% in the light absorption has been achieved thanks to the nanopattern which, in turn, increased the short circuit current from 20.6 mA/cm2 to 23.8 mA/cm2. The efficiency, on the other hand, has limitedly increased from 6.4% to 6.7%. We show using the transfer length method (TLM) that the surface topography modification caused by the nanopattern has increased the sheet resistance of the antireflection coating (ARC) layer as well as the contact resistance between the ARC layer and the emitter front contacts. This, in turn, resulted in increased series resistance of the nanopatterned cell which has translated into a decreased fill factor, explaining the limited increase in efficiency.

In the frame of the development of thin crystalline silicon solar cell technologies, surface nanopattening of silicon is gaining importance. Its impact on the material quality is however not yet fully controlled. We investigate here the influence of surface nanotexturing on the series resistance of a contacting scheme relevant for thin-film crystalline silicon heterojunction solar cells. Two-dimensional periodic nanotextures are fabricated using a combination of nanoimprint lithography and either dry or wet etching, while random pyramid texturing is used for benchmarking. We compare these texturing techniques in terms of their effect on the series resistance of a solar cell, through a study of the sheet resistance (Rsh) and contact resistance (Rc) of its front layers i.e. a sputtered transparent conductive oxide and evaporated metal contacts. We have found by four-point probe and the transfer length methods that dry-etched nanopatterns render the highest Rsh and Rc values. Wet-etched nanopatterns, on the other hand, have less impact on Rc and render Rsh similar to that obtained from the nontextured case.

No abstract

No abstract

No abstract

No abstract