Color-tunable transparent silicon solar cell with 7.38% performance

• Developed for BIPV applications by scientists in Korea, the solar cell is based on a 100μm-thick n-type silicon wafer as well as has a bending radius of 3-6mm.

Researchers at South Korea's Ulsan National Institute of Science and Technology (UNIST) have actually demonstrated a highly transparent, colorful solar cell based upon silicon that they claim programs unmatched flexibility incorporated with exceptional power conversion effectiveness.

Developed for applications in building-integrated photovoltaics (BIPV), the solar cell was made to be developed with a 100μm-thick n-Si wafer and by punching, by means of photolithography, micro-holes that can enable light to be sent through the cell itself.

The holes are arranged in the form of a periodic array within the tool, which makes certain, according to the study team, that the cell is highly flexible, with a bending radius of 6mm. "The periodic opening array structure uniformly disperses the stress and anxiety across the tool and also reduces the generation as well as breeding of microcracks," they described, noting that the structure was implemented by controlling the dry engraving procedure.

In order to make the cell colorful, the researchers added natural dyes into its polydimethylsiloxane (PDMS) matrix. PDMS is an organic-based polymer that is commonly used in solar component backsheets. After it was embedded in the cell, nevertheless, the bending radius lowered to 3mm.

The demonstrated device accomplished a power conversion efficiency of 7.38% with an average noticeable light passage (AVT) of 45%, as well as an efficiency of 5.52% with an AVT of 60%. "The solar cells with PDMS encapsulation reveal high flexibility and long-lasting stability without significant degradation, also after cyclic bending deformations up to 1,000 cycles as well as 1,500 hrs of the typical wet heat examination," the academics emphasized.

The solar cell exists in the paper Colorful Transparent Silicon Photovoltaics with Unprecedented Flexibility, which was recently published in Advanced Functional Products.