Biomimetic diodon-skin nanothorn polymer antireflection film for solar cell applications

A biomimetic diodon-skin nanothorn (DSNT) epoxy resin antireflection (AR) film was presented to reduce the incident reflection loss of Si solar cell and thus improve power conversion efficiency (PCE). The fabricated epoxy resin DSNT film, designed using finite-difference time-domain method, was added on bare Si substrate using a polydimethylsiloxane (PDMS) stamps with soft imprint lithography. Optical characteristics showed the reflection was reduced in wavelength range of 300–1100 nm from 40.0% of bare Si substrate to 15.8% of epoxy resin DSNT film/Si substrate. In addition, we found the designed DSNT structure can be facilely transferred onto any flat substrates without deformation into unexpected shapes using soft imprint lithography. Moreover, the epoxy resin DSNT film exhibited superior hydrophobic and self-cleaning properties. By introducing the epoxy resin DSNT film on top of Si solar cell, the reflection loss of the Si solar cell was reduced by 7.8% and thus the PCE was increased from 18.99% to 19.88%. Thus, the epoxy resin DSNT film is a good candidate of AR film for photovoltaic application.